



1.1  Jochen Koenigsmann (Reino Unido) Decidability in local and global fields Resumo: This lecture highlights some recent advances on classical decidability issues in local and global fields.  
1.2  Joris van der Hoeven (França), Matthias Aschenbrenner (EUA) e Lou van den Dries (EUA) On numbers, germs, and transseries Resumo: Germs of realvalued functions, surreal numbers, and transseries are three ways to enrich the real continuum by infinitesimal and infinite quantities. Each of these comes with naturally interacting notions of ordering and derivative. The category of $H$fields provides a common framework for the relevant algebraic structures. We give an exposition of our results on the model theory of $H$fields, and we report on recent progress in unifying germs, surreal numbers, and transseries from the point of view of asymptotic differential algebra.  
1.3  Maryanthe Malliaris (EUA) Model theory and ultraproducts Resumo: The article motivates recent work on saturation of ultrapowers from a general mathematical point of view.  
1.4  Stephen Jackson (EUA) Towards a theory of definable sets Resumo: The subject of descriptive set theory is traditionally concerned with the theory of definable subsets of Polish spaces. By introducing large cardinal/determinacy axioms, a theory of definable subsets of Polish spaces and their associated ordinals has been developed over the last several decades which extends far up in the definability hierarchy. Recently, much interest has been focused on trying to extend the theory of definable objects to more general types of sets, not necessarily subsets of a Polish space or an ordinal. A large class of these objects are represented by equivalence relations on Polish spaces. Even for some of the simpler of these relations, an interesting combinatorial theory is emerging. We consider both problems of extending further the theory of definable subsets of Polish spaces, and that of determining the structure of these new types of definable sets.  
1.5  Ulrich Kohlenbach (Alemanha) Prooftheoretic methods in nonlinear analysis Resumo: We discuss applications of methods from proof theory, socalled proof interpretations, for the extraction of explicit bounds in convex optimization, fixed point theory, ergodic theory and nonlinear semigroup theory. 
2.1  Ivan Panin (Rússia) On Grothendieck–Serre conjecture concerning principal bundles Resumo: Let $R$ be a regular local ring. Let $\bf G$ be a reductive group scheme over $R$. A wellknown conjecture due to Grothendieck and Serre assertes that a principal $\bf G$bundle over $R$ is trivial, if it is trivial over the fraction field of $R$. In other words, if $K$ is the fraction field of $R$, then the map of nonabelian cohomology pointed sets \[ {H}^1_{ét}(R,{\bf G})\to {H}^1_{ét}(K,{\bf G}) \] induced by the inclusion of $R$ into $K$, has a trivial kernel. The conjecture is solved in positive for all regular local rings contaning a field. More precisely, if the ring $R$ contains an infinite field, then this conjecture is proved in a joint paper due to R. Fedorov and I. Panin published in 2015 in Publications l'IHES. If the ring R contains a finite field, then this conjecture is proved in 2015 in a preprint due to I. Panin which can be found on preprint server Linear Algebraic Groups and Related Structures. A more structured exposition can be found in Panin's preprint of the year 2017 on arXiv.org. This and other results concerning the conjecture are discussed in the present paper. We illustrate the exposition by many interesting examples. We begin with couple results for complex algebraic varieties and develop the exposition step by step to its full generality.  
2.2  Moritz Kerz (Alemanha) On negative algebraic $K$groups Resumo: We sketch a proof of Weibel's conjecture on the vanishing of negative algebraic $K$groups and we explain an analog of this result for continuous $K$theory of nonarchimedean algebras.  
2.3  Osamu Iyama (Japão) Tilting Cohen–Macaulay representations Resumo: This is a survey on recent developments in Cohen–Macaulay representations via tilting and cluster tilting theory. We explain triangle equivalences between the singularity categories of Gorenstein rings and the derived (or cluster) categories of finite dimensional algebras.  
2.4  Pham Tiep (EUA/Vietnã) Representations of finite groups and applications Resumo: We discuss some basic problems in representation theory of finite groups, and current approaches and recent progress on some of these problems. We will also outline some applications of these and other results in representation theory of finite groups to various problems in group theory, number theory, and algebraic geometry.  
2.5  Sonia Natale (Argentina) On the classification of fusion categories Resumo: We report, from an algebraic point of view, on some methods and results on the classification problem of fusion categories over an algebraically closed field of characteristic zero.  
7.11  2.6  Christof Geiß (México) Quivers with relations for symmetrizable Cartan matrices and algebraic Lie theory Resumo: We give an overview of our effort to introduce (dual) semicanonical bases in the setting of symmetrizable Cartan matrices. 
13.1  3.1  Maryna Viazovska (Suíça) Sharp sphere packings Resumo: In this talk we will speak about recent progress on the sphere packing problem. The packing problem can be formulated for a wide class of metric spaces equipped with a measure. An interesting feature of this optimization problem is that a slight change of parameters (such as the dimension of the space or radius of the spheres) can dramatically change the properties of optimal configurations. We will focus on those cases when the solution of the packing problem is particularly simple. Namely, we say that a packing problem is sharp if its density attains the socalled linear programming bound. Several such configurations have been known for a long time and we have recently proved that the $E_8$ lattice sphere packing in $\mathbb{R}^8$ and the Leech lattice packing in $\mathbb{R}^{24}$ are sharp. Moreover, we will discuss common unusual properties of shared by such configurations and outline possible applications to Fourier analysis. 
3.2  James Maynard (Reino Unido) Gaps between primes Resumo: We discuss recent advances on weak forms of the Prime $k$tuple Conjecture, and its role in proving new estimates for the existence of small gaps between primes and the existence of large gaps between primes.  
3.3  Adrian Iovita (Canadá/Itália), Fabrizio Andreatta (Itália) e Vincent Pilloni (França) $p$adic variation of automorphic sheaves Resumo: We review the construction of analytic families of Siegel modular cuspforms based on the notion of overconvergent modular forms of $p$adic weight. We then present recent developments on the following subjects: the halo conjecture, the construction of $p$adic Lfunctions, and the modularity of irregular motives.  
4.4  3.4  Laurent Fargues (França) La courbe Resumo: On présente un résumé de nos travaux sur la courbe que nous avons introduite avec JeanMarc Fontaine et ses applications en théorie de Hodge $p$adique ainsi qu'au programme de Langlands. 
3.5  Maksym Radziwiłł (Canadá) e Kaisa Matomäki (Finlândia) Multiplicative functions in short intervals, and correlations of multiplicative functions Resumo: Our goal in this note is twofold. In part I, we motivate and explain the ideas behind a recent theorem of ours. Theorem [Matomäki–Radziwiłł]: Let $f$ be a realvalued multiplicative function with $f \leq 1$. Then, for all $X < x \leq 2X$, with at most $o(X)$ exceptions, $$ \frac{1}{H} \sum_{x < x \leq x + H} f(n)  \frac{1}{X} \sum_{X < n \leq 2 X} f(n) = o(1) $$ as soon as $H \rightarrow \infty$ with $X \rightarrow \infty$. In part II, which can be read independently, our goal is to survey some of the recent developments connected to the theorem. These have been by far and large related to Chowla's conjecture. Conjecture[Chowla]: Let $\mu$ denote the Möbius function. Then, for any set of distinct integers $h_1, \ldots, h_k$, $$ \sum_{n \leq X} \mu(n + h_1) \ldots \mu(n + h_k) = o(X) $$ as $X \rightarrow \infty$.  
3.6  Bjorn Poonen (EUA) Heuristics for the arithmetic of elliptic curves Resumo: This is an introduction to a probabilistic model for the arithmetic of elliptic curves, a model developed in a series of articles of the author with Bhargava, Kane, Lenstra, Park, Rains, Voight, and Wood. We discuss the theoretical evidence for the model, and we make predictions about elliptic curves based on corresponding theorems proved about the model. In particular, the model suggests that all but finitely many elliptic curves over $\mathbb{Q}$ have rank $\le 21$, which would imply that the rank is uniformly bounded.  
3.7  Ritabrata Munshi (Índia) The subconvexity problem for $L$functions Resumo: Estimating the size of automorphic $L$functions on the critical line is a central problem in analytic number theory. An easy consequence of the standard analytic properties of the $L$function is the convexity bound, whereas the generalised Riemann Hypothesis predicts a much sharper bound. Breaking the convexity barrier is a hard problem. The moment method has been used to surpass convexity in the case of $L$functions of degree one and two. In this talk I will discuss a different method, which has been quite successful to settle certain longstanding open problems in the case of degree three.  
4.11  3.8  Georgios Pappas (EUA) Arithmetic models for Shimura varieties Resumo: We describe recent work on the construction of wellbehaved arithmetic models for large classes of Shimura varieties and report on progress in the study of these models. 
9.14  3.9  Miguel Walsh (Argentina) Characteristic subsets and the polynomial method Resumo: We provide an informal discussion of the polynomial method. This is a tool of general applicability that can be used to exploit the algebraic structure arising in some problems of arithmetic nature. 
3.10  Wei Zhang (EUA) Sharp sphere packings Resumo: In this talk we will speak about recent progress on the sphere packing problem. The packing problem can be formulated for a wide class of metric spaces equipped with a measure. An interesting feature of this optimization problem is that a slight change of parameters (such as the dimension of the space or radius of the spheres) can dramatically change the properties of optimal configurations. We will focus on those cases when the solution of the packing problem is particularly simple. Namely, we say that a packing problem is sharp if its density attains the socalled linear programming bound. Several such configurations have been known for a long time and we have recently proved that the $E_8$ lattice sphere packing in $\mathbb{R}^8$ and the Leech lattice packing in $\mathbb{R}^{24}$ are sharp. Moreover, we will discuss common unusual properties of shared by such configurations and outline possible applications to Fourier analysis.  
3.11  Yves André (França) Perfectoid spaces and the homological conjectures Resumo: This is a survey of recent advances in commutative algebra, especially in mixed characteristic, obtained by using the theory of perfectoid spaces. An explanation of these techniques and a short account of the author's proof of the direct summand conjecture are included. One then portrays the progresses made with these (and related) techniques on the socalled homological conjectures.  
3.12  Jack Thorne (Reino Unido) Potential automorphy of $\widehat{G}$local systems Resumo: Vincent Lafforgue has recently made a spectacular breakthrough in the setting of the global Langlands correspondence for global fields of positive characteristic, by constructing the ‘automorphic–to–Galois’ direction of the correspondence for an arbitrary reductive group $G$. We discuss a result that starts with Lafforgue's work and proceeds in the opposite (‘Galois–to–automorphic’) direction.  
3.13  Jacob Tsimerman (Canadá) Functional transcendence and arithmetic applications Resumo: We survey recent results in functional transcendence theory, and give arithmetic applications to the André–Oort conjecture and other unlikelyintersection problems. 
8.1  4.1  Sébastien Boucksom (França) Variational and nonArchimedean aspects of the Yau–Tian–Donaldson conjecture Resumo: We survey some recent developments in the direction of the Yau–Tian–Donaldson conjecture, which relates the existence of constant scalar curvature Kähler metrics to the algebrogeometric notion of Kstability. The emphasis is put on the use of pluripotential theory and the interpretation of Kstability in terms of nonArchimedean geometry. 
4.2  Caucher Birkar (Reino Unido) Birational geometry of algebraic varieties Resumo: This is a report on some of the main developments in birational geometry in recent years focusing on the minimal model program, Fano varieties, singularities and related topics, in characteristic zero.  
4.3  Lucia Caporaso (Itália) Recursive combinatorial aspects of compactified moduli spaces Resumo: In recent years an interesting connection has been established between some moduli spaces of algebrogeometric objects (e.g. algebraic stable curves) and some moduli spaces of polyhedral objects (e.g. tropical curves). In loose words, this connection expresses the Berkovich skeleton of a given algebrogeometric moduli space as the moduli space of the skeleta of the objects parametrized by the given space; it has been proved to hold in two important cases: the moduli space of stable curves and the moduli space of admissible covers. Partial results are known in other cases. This connection relies on the study of the boundary of the algebrogeometric moduli spaces and on its recursive, combinatorial properties, some of which have been long known and are now viewed from a new perspective.  
3.4  4.4  Laurent Fargues (França) La courbe Resumo: On présente un résumé de nos travaux sur la courbe que nous avons introduite avec JeanMarc Fontaine et ses applications en théorie de Hodge $p$adique ainsi qu'au programme de Langlands. 
4.5  Chenyang Xu (China) Interaction between singularity theory and the minimal model program Resumo: We survey some recent topics on singularities, with a focus on their connection to the minimal model program. This includes the construction and properties of dual complexes, the proof of the ACC conjecture for log canonical thresholds and the recent progress on the ‘local stability theory’ of an arbitrary Kawamata log terminal singularity.  
4.6  Krzysztof Kurdyka (França) e Wojciech Kucharz (Polônia) From continuous rational to regulous functions Resumo: Let $X$ be an algebraic set in $\mathbb{R}^n$. Realvalued functions, defined on subsets of $X$, that are continuous and admit a rational representation have some remarkable properties and applications. We discuss recently obtained results on such functions, against the backdrop of previously developed theories of arcsymmetric sets, arcanalytic functions, approximation by regular maps, and algebraic vector bundles.  
4.7  Carolina Araujo (Brasil) Positivity and algebraic integrability of holomorphic foliations Resumo: The theory of holomorphic foliations has its origins in the study of differential equations on the complex plane, and has turned into a powerful tool in algebraic geometry. One of the fundamental problems in the theory is to find conditions that guarantee that the leaves of a holomorphic foliation are algebraic. These correspond to algebraic solutions of differential equations. In this paper we discuss algebraic integrability criteria for holomorphic foliations in terms of positivity of its tangent sheaf, and survey the theory of Fano foliations, developed in a series of papers in collaboration with Stéphane Druel. We end by classifying all possible leaves of del Pezzo foliations.  
6.4  4.8  András Némethi (Hungria) Pairs of invariants of surface singularities Resumo: We discuss several invariants of complex normal surface singularities with a special emphasis on the comparison of analytic–topological pairs of invariants. Additionally we also list several open problems related with them. 
4.9  Jungkai Chen (Taiwan) e Meng Chen (China) On explicit aspect of pluricanonical maps of projective varieties Resumo: In this survey article, we introduce the development of birational geometry associated to pluricanonical maps. Especially, we explain various aspects of explicit studies of threefolds including the key idea of theory of baskets and other applications.  
4.10  Mihnea Popa (EUA) Variational and nonArchimedean aspects of the Yau–Tian–Donaldson conjecture Resumo: We survey some recent developments in the direction of the Yau–Tian–Donaldson conjecture, which relates the existence of constant scalar curvature Kähler metrics to the algebrogeometric notion of Kstability. The emphasis is put on the use of pluripotential theory and the interpretation of Kstability in terms of nonArchimedean geometry.  
3.8  4.11  Georgios Pappas (EUA) Arithmetic models for Shimura varieties Resumo: We describe recent work on the construction of wellbehaved arithmetic models for large classes of Shimura varieties and report on progress in the study of these models. 
9.13  4.12  Serge Cantat (França) Automorphisms of K3 surfaces Resumo: Holomorphic diffeomorphisms of K3 surfaces have nice dynamical properties. I will survey the main theorems concerning their dynamical behavior: most of them were proved during the past twenty years, and many open questions remain. This will be a mix of algebraic geometry, dynamical systems, with some real algebraic geometry on the way. 
4.13  Dan Abramovich (EUA/Israel) Resolution of singularities of complex algebraic varieties and their families Resumo: We discuss Hironaka's theorem on resolution of singularities in charactetistic 0 as well as more recent progress, both on simplifying and improving Hironaka's method of proof and on new results and directions on families of varieties, leading to joint work on toroidal orbifolds with Michael Temkin and Jarosław Włodarczyk.  
4.14  JongHae Keum (Coréia do Sul) Algebraic surfaces with minimal Betti numbers Resumo: These are algebraic surfaces with the Betti numbers of the complex projective plane, and are called $\mathbb{Q}$homology projective planes. Fake projective planes and the complex projective plane are smooth examples. We describe recent progress in the study of such surfaces, singular ones and fake projective planes. We also discuss open questions.  
4.15  Sean Keel (EUA) e Paul Hacking (EUA) Mirror symmetry and cluster algebras Resumo: We explain our proof, joint with Mark Gross and Maxim Kontsevich, of conjectures of Fomin–Zelevinsky and Fock–Goncharov on canonical bases of cluster algebras. We interpret a cluster algebra as the ring of global functions on a noncompact Calabi–Yau variety obtained from a toric variety by a blow up construction. We describe a canonical basis of a cluster algebra determined by tropical counts of holomorphic discs on the mirror variety, using the algebraic approach to the Strominger–Yau–Zaslow conjecture due to Gross and Siebert.  
7.10  4.16  Zhiwei Yun (EUA) Hitchin type moduli stacks in automorphic representation theory Resumo: In the study of automorphic representations over a function field, Hitchin moduli stack and its variants naturally appear and their geometry helps the comparison of trace formulae. We give a survey on applications of this observation to a relative fundamental lemma, the arithmetic fundamental lemma and to the higher Gross–Zagier formula. 
5.1  Nicolas Bergeron (França) Hodge theory and cycle theory of locally symmetric spaces Resumo: We discuss several results pertaining to the Hodge and cycle theories of locally symmetric spaces. The unity behind these results is motivated by a vague but fruitful analogy between locally symmetric spaces and projective varieties.  
8.2  5.2  Bo Berndtsson (Suécia) Complex Brunn–Minkowski theory and positivity of vector bundles Resumo: This is a survey of results on positivity of vector bundles, inspired by the Brunn–Minkowski and Prékopa theorems. Applications to complex analysis, Kähler geometry and algebraic geometry are also discussed. 
5.3  Denis Osin (EUA) Groups acting acylindrically on hyperbolic spaces Resumo: The goal of this article is to survey some recent developments in the study of groups acting on hyperbolic spaces. We focus on the class of acylindrically hyperbolic groups; it is broad enough to include many examples of interest, yet a significant part of the theory of hyperbolic and relatively hyperbolic groups can be generalized in this context. In particular, we discuss group theoretic Dehn filling and small cancellation theory in acylindrically hyperbolic groups. Many results discussed here rely on the new generalization of relative hyperbolicity based on the notion of a hyperbolically embedded subgroup.  
5.4  Umberto Hryniewicz (Brasil) e Pedro Salomão (Brasil) Global surfaces of section for Reeb flows in dimension three and beyond Resumo: We survey some recent developments in the quest for global surfaces of section for Reeb flows in dimension three using methods from Symplectic Topology. We focus on applications to geometry, including existence of closed geodesics and sharp systolic inequalities. Applications to topology and celestial mechanics are also presented.  
6.1  5.5  Ciprian Manolescu (EUA) Homology cobordism and triangulations Resumo: The study of triangulations on manifolds is closely related to understanding the threedimensional homology cobordism group. We review here what is known about this group, with an emphasis on the local equivalence methods coming from $Pin(2)$equivariant Seiberg–Witten Floer spectra and involutive Heegaard Floer homology. 
6.2  5.6  Emmy Murphy (EUA) Flexibility in symplectic and contact geometry Resumo: N/A 
6.3  5.7  Tobias Ekholm (Suécia) Knot contact homology and open Gromov–Witten theory Resumo: Knot contact homology studies symplectic and contact geometric properties of conormals of knots in 3manifolds using holomorphic curve techniques. It has connections to both mathematical and physical theories. On the mathematical side, we review the theory, show that it gives a complete knot invariant, and discuss its connections to Fukaya categories, string topology, and microlocal sheaves. On the physical side, we describe the connection between the augmentation variety of knot contact homology and Gromov–Witten disk potentials, and discuss the corresponding higher genus relation that quantizes the augmentation variety. 
5.8  Ivan Smith (Reino Unido) Stability conditions in symplectic topology Resumo: We discuss potential (largely speculative) applications of Bridgeland's theory of stability conditions to symplectic mapping class groups.  
5.9  Mahan Mj (Índia) Cannon–Thurston maps Resumo: We give an overview of the theory of Cannon–Thurston maps which forms one of the links between the complex analytic and hyperbolic geometric study of Kleinian groups. We also briefly sketch connections to hyperbolic subgroups of hyperbolic groups and end with some open questions.  
5.10  Song Sun (EUA) Hodge theory and cycle theory of locally symmetric spaces Resumo: We discuss several results pertaining to the Hodge and cycle theories of locally symmetric spaces. The unity behind these results is motivated by a vague but fruitful analogy between locally symmetric spaces and projective varieties.  
5.11  Anna Wienhard (Alemanha) An invitation to higher Teichmüller theory Resumo: Riemann surfaces are of fundamental importance in many areas of mathematics and theoretical physics. The study of the moduli space of Riemann surfaces of a fixed topological type is intimately related to the study of the Teichmüller space of that surface, together with the action of the mapping class group. Classical Teichmüller theory has many facets and involves the interplay of various methods from geometry, analysis, dynamics and algebraic geometry. In recent years, higher Teichmüller theory emerged as a new field in mathematics. It builds as well on a combination of methods from different areas of mathematics. The goal of my talk is to invite the reader to get to know and to get involved into higher Teichmüller theory by describing some of its many facets.  
10.11  5.12  Eugenia Malinnikova (Noruega) e Alexander Logunov (Israel/Rússia) Quantitative propagation of smallness for solutions of elliptic equations Resumo: Let $u$ be a solution to an elliptic equation $div(A\nabla u)=0$ with Lipschitz coefficients in $\mathbb{R}^n$. Assume $u$ is bounded by $1$ in the ball $B=\{x\leq 1\}$. We show that if $u < \varepsilon$ on a set $ E \subset \frac{1}{2} B$ with positive $n$dimensional Hausdorf measure, then $$u\leq C\varepsilon^\gamma \quad \mbox{on} \quad \frac{1}{2}B$$ where $C>0, \gamma \in (0,1)$ do not depend on $u$ and depend only on $A$ and the measure of $E$. We specify the dependence on the measure of $E$ in the form of the Remez type inequality. Similar estimate holds for sets $E$ with Hausdorff dimension bigger than $n1$. For the gradients of the solutions we show that a similar propagation of smallness holds for sets of Hausdorff dimension bigger than $n1c$, where $c>0$ is a small numerical constant depending on the dimension only. 
5.5  6.1  Ciprian Manolescu (EUA) Homology cobordism and triangulations Resumo: The study of triangulations on manifolds is closely related to understanding the threedimensional homology cobordism group. We review here what is known about this group, with an emphasis on the local equivalence methods coming from $Pin(2)$equivariant Seiberg–Witten Floer spectra and involutive Heegaard Floer homology. 
5.6  6.2  Emmy Murphy (EUA) Flexibility in symplectic and contact geometry Resumo: N/A 
5.7  6.3  Tobias Ekholm (Suécia) Knot contact homology and open Gromov–Witten theory Resumo: Knot contact homology studies symplectic and contact geometric properties of conormals of knots in 3manifolds using holomorphic curve techniques. It has connections to both mathematical and physical theories. On the mathematical side, we review the theory, show that it gives a complete knot invariant, and discuss its connections to Fukaya categories, string topology, and microlocal sheaves. On the physical side, we describe the connection between the augmentation variety of knot contact homology and Gromov–Witten disk potentials, and discuss the corresponding higher genus relation that quantizes the augmentation variety. 
4.8  6.4  András Némethi (Hungria) Pairs of invariants of surface singularities Resumo: We discuss several invariants of complex normal surface singularities with a special emphasis on the comparison of analytic–topological pairs of invariants. Additionally we also list several open problems related with them. 
11.3  6.5  Thomas Willwacher (Suíça) Little disks operads and Feynman diagrams Resumo: The little disks operads are classical objects in algebraic topology which have seen a wide range of applications in the past. For example they appear prominently in the Goodwillie–Weiss embedding calculus, which is a program to understand embedding spaces through algebraic properties of the little disks operads, and their action on the spaces of configurations of points (or disks) on manifolds. In this talk we review the recent understanding of the rational homotopy theory of the little disks operads, and how the resulting knowledge can be used to fulfil the promise of the Goodwillie–Weiss calculus, at least in the “simple” setting of long knot spaces and over the rationals. The derivations prominently use and are connected to graph complexes, introduced by Kontsevich and other authors. 
8.9  6.6  Andreas Thom (Alemanha) Finitary approximations of groups and their applications Resumo: In these notes we will survey recent results on various finitary approximation properties of infinite groups. We will discuss various restrictions on groups that are approximated for example by finite solvable groups or finitedimensional unitary groups with the Frobenius metric. Towards the end, we also briefly discuss various applications of those approximation properties to the understanding of the equational theory of a group. 
6.7  Alan Reid (EUA) Profinite rigidity Resumo: We survey recent work on profinite rigidity of residually finite groups.  
6.8  Arthur Bartels (Alemanha) $K$theory and actions on Euclidean retracts Resumo: This note surveys axiomatic results for the Farrell–Jones Conjecture in terms of actions on Euclidean retracts and applications of these to $GL_n(\mathbb{Z})$, relative hyperbolic groups and mapping class groups.  
6.9  Bernardo Uribe (Colômbia) The evenness conjecture in equivariant unitary bordism Resumo: The evenness conjecture for the equivariant unitary bordism groups states that these bordism groups are free modules over the unitary bordism ring in even dimensional generators. In this paper we review the cases on which the conjecture is known to hold and we highlight the properties that permit to prove the conjecture in these cases.  
6.10  Fanny Kassel (França) Homology cobordism and triangulations Resumo: The study of triangulations on manifolds is closely related to understanding the threedimensional homology cobordism group. We review here what is known about this group, with an emphasis on the local equivalence methods coming from $Pin(2)$equivariant Seiberg–Witten Floer spectra and involutive Heegaard Floer homology.  
6.11  Sucharit Sarkar (EUA) e Robert Lipshitz (EUA) Spatial refinements and Khovanov homology Resumo: We review the construction and context of a stable homotopy refinement of Khovanov homology.  
6.12  Koji Fujiwara (Japão) Constructing group actions on quasitrees Resumo: A quasitree is a geodesic metric space quasiisometric to a tree. We give a general construction of many actions of groups on quasitrees. The groups we can handle include nonelementary hyperbolic groups, CAT(0) groups with rank 1 elements, mapping class groups and the outer automorphism groups of free groups. As an application, we show that mapping class groups act on finite products of Gromovhyperbolic spaces so that orbit maps are quasiisometric embeddings. It implies that mapping class groups have finite asymptotic dimension.  
6.13  John Pardon (EUA) Cosheaves of wrapped Fukaya categories Resumo: N/A 
7.1  Olivier Schiffmann (França) Hitchin type moduli stacks in automorphic representation theory Resumo: In the study of automorphic representations over a function field, Hitchin moduli stack and its variants naturally appear and their geometry helps the comparison of trace formulae. We give a survey on applications of this observation to a relative fundamental lemma, the arithmetic fundamental lemma and to the higher Gross–Zagier formula.  
7.2  Tomoyuki Arakawa (Japão) Representation theory of Walgebras and Higgs branch conjecture Resumo: We survey a number of results regarding the representation theory of $W$algebras and their connection with the resent development of the four dimensional $N=2$ superconformal field theories.  
7.3  Vyacheslav Futorny (Brasil) Representations of Galois algebras Resumo: Galois algebras allow an effective study of their representation theory based on the invariant skew group structure. In particular, this leads to many remarkable results on Gelfand–Tsetlin representations of the general linear Lie algebra $\mathfrak{gl}_n$, quantum $\mathfrak{gl}_n$, Yangians of type $A$ and finite $W$algebras of type $A$.  
7.4  Tsachik Gelander (Israel) A view on invariant random subgroups and lattices Resumo: For more than half a century lattices in Lie groups played an important role in geometry, number theory and group theory. Recently the notion of Invariant Random Subgroups (IRS) emerged as a natural generalization of lattices. It is thus intriguing to extend results from the theory of lattices to the context of IRS, and to study lattices by analyzing the compact space of all IRS of a given group. This article focuses on the interplay between lattices and IRS, mainly in the classical case of semisimple analytic groups over local fields.  
7.5  Dipendra Prasad (Índia) Extanalogues of Branching laws Resumo: We consider the Extanalogues of branching laws for representations of a group to its subgroups in the context of $p$adic groups.  
7.6  Eva Viehmann (Alemanha) Moduli spaces of local $\mathbf G$shtukas Resumo: We give an overview of the theory of local $\mathbf{G}$shtukas and their moduli spaces that were introduced in joint work of U. Hartl and the author, and in the past years studied by many people. We also discuss relations to moduli of global $\mathbf{G}$shtukas, properties of their special fiber through affine Deligne–Lusztig varieties and of their generic fiber, such as the period map.  
7.7  Michael Finkelberg (Rússia) Double affine Grassmannians and Coulomb branches of $3d \mathcal{N}=4$ quiver gauge theories Resumo: We propose a conjectural construction of various slices for double affine Grassmannians as Coulomb branches of 3dimensional $\mathcal{N}=4$ supersymmetric affine quiver gauge theories. It generalizes the known construction for the usual affine Grassmannians, and makes sense for arbitrary symmetric Kac–Mody algebras.  
7.8  Xuhua He (EUA) Some results on affine Deligne–Lusztig varieties Resumo: The study of affine Deligne–Lusztig varieties originally arose from arithmetic geometry, but many problems on affine Deligne–Lusztig varieties are purely Lietheoretic in nature. This survey deals with recent progress on several important problems on affine Deligne–Lusztig varieties. The emphasis is on the Lietheoretic aspect, while some connections and applications to arithmetic geometry will also be mentioned.  
7.9  Akshay Venkatesh (EUA) N/A Resumo: N/A  
4.16  7.10  Zhiwei Yun (EUA) Hitchin type moduli stacks in automorphic representation theory Resumo: In the study of automorphic representations over a function field, Hitchin moduli stack and its variants naturally appear and their geometry helps the comparison of trace formulae. We give a survey on applications of this observation to a relative fundamental lemma, the arithmetic fundamental lemma and to the higher Gross–Zagier formula. 
2.6  7.11  Christof Geiß (México) Quivers with relations for symmetrizable Cartan matrices and algebraic Lie theory Resumo: We give an overview of our effort to introduce (dual) semicanonical bases in the setting of symmetrizable Cartan matrices. 
4.1  8.1  Sébastien Boucksom (França) Variational and nonArchimedean aspects of the Yau–Tian–Donaldson conjecture Resumo: We survey some recent developments in the direction of the Yau–Tian–Donaldson conjecture, which relates the existence of constant scalar curvature Kähler metrics to the algebrogeometric notion of Kstability. The emphasis is put on the use of pluripotential theory and the interpretation of Kstability in terms of nonArchimedean geometry. 
5.2  8.2  Bo Berndtsson (Suécia) Complex Brunn–Minkowski theory and positivity of vector bundles Resumo: This is a survey of results on positivity of vector bundles, inspired by the Brunn–Minkowski and Prékopa theorems. Applications to complex analysis, Kähler geometry and algebraic geometry are also discussed. 
10.3  8.3  Guido De Philippis (Itália) On the structure of measures constrained by linear PDEs Resumo: The aim of this note is to present some recent results on the structure of the singular part of measures satisfying a PDE constraint and to describe some applications. 
11.1  8.4  Yasuyuki Kawahigashi (Japão) Conformal field theory, vertex operator algebras and operator algebras Resumo: We present recent progress in theory of local conformal nets which is an operator algebraic approach to study chiral conformal field theory. We emphasize representation theoretic aspects and relations to theory of vertex operator algebras which gives a different and algebraic formulation of chiral conformal field theory. 
8.5  Adrian Ioana (EUA) Rigidity for von Neumann algebras Resumo: We survey some of the progress made recently in the classification of von Neumann algebras arising from countable groups and their measure preserving actions on probability spaces. We emphasize results which provide classes of (W$^*$superrigid) actions that can be completely recovered from their von Neumann algebras and II$_1$ factors that have a unique Cartan subalgebra. We also present cocycle superrigidity theorems and some of their applications to orbit equivalence. Finally, we discuss several recent rigidity results for von Neumann algebras associated to groups.  
8.6  Ruy Exel (Brasil) Conformal and DLR measures on Markov subshifts with infinitely many states Resumo: We shall begin by briefly reviewing a compactification of the Markov space for an infinite transition matrix, introduced by Marcelo Laca and the speaker roughly 20 years ago. Given a continuous potential we will then consider the problem of characterizing the conformal measures on that space. An example will be presented to show that conformal measures may live in the complement of the standard Markov space, hence being invisible to the standard theory. Along the way a somewhat unexpected but very natural generalization of Renault's notion of approximately proper equivalence relations will force its way into the picture leading up to the construction of a natural étale groupoid whose quasiinvariant measures we shall also discuss observing that they are examples of what may be seen as generalized DLR (Dobrushin–Lanford–Ruelle) measures. In the context of the Markov shifts mentioned above we will then explore the connections between conformal and DLR measures. This talk is based on ongoing joint work with Rodrigo Bissacot, Rodrigo Frausino and Thiago Raszeja from University of São Paulo.  
12.8  8.7  Dmitry Chelkak (França/Rússia) Planar Ising model at criticality: Stateoftheart and perspectives Resumo: In this essay, we briefly discuss recent developments, started a decade ago in the seminal work of Smirnov and continued by a number of authors, centered around the conformal invariance of the critical planar Ising model on $\mathbb{Z}^2$ and, more generally, of the critical Zinvariant Ising model on isoradial graphs (rhombic lattices). We also introduce a new class of embeddings of general weighted planar graphs (sembeddings), which might, in particular, pave the way to true universality results for the planar Ising model. 
8.8  András Máthé (Reino Unido) Measurable equidecompositions Resumo: The famous Banach–Tarski paradox and Hilbert's third problem are part of story of paradoxical equidecompositions and invariant finitely additive measures. We review some of the classical results in this area including Laczkovich's solution to Tarski's circlesquaring problem: the disc of unit area can be cut into finitely many pieces that can be rearranged by translations to form the unit square. We also discuss the recent developments that in certain cases the pieces can be chosen to be Lebesgue measurable or Borel: namely, a measurable Banach–Tarski ‘paradox’ and the existence of measurable/Borel circlesquaring.  
6.6  8.9  Andreas Thom (Alemanha) Finitary approximations of groups and their applications Resumo: In these notes we will survey recent results on various finitary approximation properties of infinite groups. We will discuss various restrictions on groups that are approximated for example by finite solvable groups or finitedimensional unitary groups with the Frobenius metric. Towards the end, we also briefly discuss various applications of those approximation properties to the understanding of the equational theory of a group. 
8.10  Stefanie Petermichl (França) Variational and nonArchimedean aspects of the Yau–Tian–Donaldson conjecture Resumo: We survey some recent developments in the direction of the Yau–Tian–Donaldson conjecture, which relates the existence of constant scalar curvature Kähler metrics to the algebrogeometric notion of Kstability. The emphasis is put on the use of pluripotential theory and the interpretation of Kstability in terms of nonArchimedean geometry.  
8.11  Ciprian Demeter (EUA) Decouplings and applications Resumo: We describe a Fourier analytic tool that has found a large number of applications in Number Theory, Harmonic Analysis and PDEs.  
8.12  Christopher Bishop (EUA) Harmonic measure: Algorithms and applications Resumo: This is a brief survey of results related to planar harmonic measure, roughly from Makarov's results of the 1980's to recent applications involving 4manifolds, {dessins d'enfants} and transcendental dynamics. It is nonchronological and rather selective, but I hope that it still illustrates various areas in analysis, topology and algebra that are influenced by harmonic measure, the computational questions that arise, the many open problems that remain, and how these questions bridge the gaps between pure/applied and discrete/continuous mathematics.  
8.13  TienCuong Dinh (Cingapura) Pluripotential theory and complex dynamics in higher dimension Resumo: Positive closed currents, the analytic counterpart of effective cycles in algebraic geometry, are central objects in pluripotential theory. They were introduced in complex dynamics in the 1990s and become now a powerful tool in the field. Challenging dynamical problems involve currents of any dimension. We will report recent developments on positive closed currents of arbitrary dimension, including the solutions to the regularization problem, the theory of superpotentials and the theory of densities. Applications to dynamics such as properties of dynamical invariants (e.g. dynamical degrees, entropies, currents, measures), solutions to equidistribution problems, and properties of periodic points will be discussed.  
8.14  Mouhamed Fall (Senegal) Constant nonlocal mean curvatures surfaces and related problems Resumo: The notion of Nonlocal Mean Curvature (NMC) appears recently in the mathematics literature. It is an extrinsic geometric quantity that is invariant under global reparameterization of a surface and provide a natural extension of the classical mean curvature. We describe some properties of the NMC and the quasilinear differential operators that are involved when it acts on graphs. We also survey recent results on surfaces having constant NMC and describe their intimate link with some problems arising in the study of overdetermined boundary value problems.  
9.16  8.15  Lewis Bowen (EUA) A brief introduction to sofic entropy theory Resumo: Sofic entropy theory is a generalization of the classical Kolmogorov–Sinai entropy theory to actions of a large class of nonamenable groups called sofic groups. This is a short introduction with a guide to the literature. 
8.16  Spiros Argyros (Grécia) e Richard Haydon (Reino Unido) Bourgain–Delbaen $\mathscr L_\infty$spaces, the scalarpluscompact property and related problems Resumo: We outline a general method of constructing $\mathscr L_\infty$spaces, based on the ideas of Bourgain and Delbaen, showing how the solution to the ScalarplusCompact Problem, the embedding theorem of Freeman, Odell and Schlumprecht and other recent developments fit into this framework.  
8.17  William Johnson (EUA) Some 20$+$ year old problems about Banach spaces and operators on them Resumo: In the last few years numerous $20+$ year old problems in the geometry of Banach spaces were solved. Some are described herein.  
8.18  Alexei Poltoratski (EUA) Toeplitz methods in completeness and spectral problems Resumo: We survey recent progress in the gap and type problems of Fourier analysis obtained via the use of Toeplitz operators in spaces of holomorphic functions. We discuss applications of such methods to spectral problems for differential operators.  
8.19  Svitlana Mayboroda (EUA) The effect of disorder and irregularities on solutions to boundary value problems and spectra of differential operators Resumo: This note describes the impact of disorder or irregularities in the ambient medium on the behavior of stationary solutions to elliptic partial differential equations and on spatial distribution of eigenfunctions, as well as the profound and somewhat surprising connections between these two topics which have been revealed in the past few years.  
8.20  Wilhelm Winter (Alemanha) Complex Brunn–Minkowski theory and positivity of vector bundles Resumo: This is a survey of results on positivity of vector bundles, inspired by the Brunn–Minkowski and Prékopa theorems. Applications to complex analysis, Kähler geometry and algebraic geometry are also discussed. 
9.1  Feliks Przytycki (Polônia) Thermodynamic formalism methods in onedimensional real and complex dynamics Resumo: We survey some results on nonuniform hyperbolicity, geometric pressure and equilibrium states in onedimensional real and complex dynamics. We present some relations with Hausdorff dimension and measures with refined gauge functions of limit sets for geometric coding trees for rational functions on the Riemann sphere. We discuss fluctuations of iterated sums of the potential $t\log f'$ and of radial growth of derivative of univalent functions on the unit disc and the boundaries of range domains preserved by a holomorphic map $f$ repelling towards the domains.  
9.2  Bassam Fayad (França) e Raphaël Krikorian (França) Some questions around quasiperiodic dynamics Resumo: We propose in these notes a list of some old and new questions related to quasiperiodic dynamics. A main aspect of quasiperiodic dynamics is the crucial influence of arithmetics on the dynamical features, with a strong duality in general between Diophantine and Liouville behavior. We will discuss rigidity and stability in Diophantine dynamics as well as their absence in Liouville ones. Beyond this classical dichotomy between the Diophantine and the Liouville worlds, we discuss some unified approaches and some phenomena that are valid in both worlds. Our focus is mainly on low dimensional dynamics such as circle diffeomorphisms, disc dynamics, quasiperiodic cocycles, or surface flows, as well as finite dimensional Hamiltonian systems. In an opposite direction, the study of the dynamical properties of some diagonal and unipotent actions on the space of lattices can be applied to arithmetics, namely to the theory of Diophantine approximations. We will mention in the last section s  
9.3  Jiangong You (China) Quantitative almost reducibility and its applications Resumo: We survey the recent advances of almost reducibility and its applications in the spectral theory of one dimensional quasiperiodic Schrödinger operators.  
9.4  Martin Möller (Alemanha) Geometry of Teichmüller curves Resumo: The study of polygonal billiard tables with simple dynamics led to a remarkable class of special subvarieties in the moduli of space of curves called Teichmüller curves, since they are totally geodesic submanifolds for the Teichmüller metric. We survey the known methods to construct of Teichmüller curves and exhibit structure theorems that might eventually lead towards the complete classification of Teichmüller curves.  
9.5  Laura DeMarco (EUA) Critical orbits and arithmetic equidistribution Resumo: These notes present recent progress on a conjecture about the dynamics of rational maps on $\mathbb{P}^1(\mathbb{C})$, connecting critical orbit relations and the structure of the bifurcation locus to the geometry and arithmetic of postcritically finite maps within the moduli space $\mathrm{M}_d$. The conjecture first appeared in a 2013 publication by Baker and DeMarco. Also presented are some related results and open questions.  
9.6  Sébastien Gouëzel (França) Subadditive cocycles and horofunctions Resumo: Subadditive cocycles are the random version of subadditive sequences. They play an important role in probability and ergodic theory, notably through Kingman's theorem ensuring their almost sure convergence. We discuss a variation around Kingman's theorem, showing that a subadditive cocycle is in fact almost additive at many times. This result is motivated by the study of the iterates of deterministic or random semicontractions on metric spaces, and implies the almost sure existence of a horofunction determining the behavior at infinity of such a sequence. In turn, convergence at infinity follows when the geometry of the space has some features of nonpositive curvature.  
9.7  Michael Hochman (Israel) Dimension theory of selfsimilar sets and measures Resumo: We report on recent results about the dimension and smoothness properties of selfsimilar sets and measures. Closely related to these are results on the linear projections of such sets, and dually, their intersections with affine subspaces. We also discuss recent progress on the the Bernoulli convolutions problem.  
9.8  Andrés Navas (Chile) Group actions on 1manifolds: A list of very concrete open questions Resumo: Over the last four decades, group actions on manifolds have deserved much attention by people coming from different fields, as for instance group theory, lowdimensional topology, foliation theory, functional analysis, and dynamical systems. This text focuses on actions on 1manifolds. We present a (non exhaustive) list of very concrete open questions in the field, each of which is discussed in some detail and complemented with a large list of references, so that a clear panorama on the subject arises from the lecture.  
9.9  Jairo Bochi (Chile) Ergodic optimization of Birkhoff averages and Lyapunov exponents Resumo: We discuss optimization of Birkhoff averages of real or vectorial functions and of Lyapunov exponents of linear cocycles, emphasizing whenever possible the similarities between the commutative and noncommutative settings.  
9.10  Lorenzo Díaz (Brasil) Thermodynamic formalism methods in onedimensional real and complex dynamics Resumo: We survey some results on nonuniform hyperbolicity, geometric pressure and equilibrium states in onedimensional real and complex dynamics. We present some relations with Hausdorff dimension and measures with refined gauge functions of limit sets for geometric coding trees for rational functions on the Riemann sphere. We discuss fluctuations of iterated sums of the potential $t\log f'$ and of radial growth of derivative of univalent functions on the unit disc and the boundaries of range domains preserved by a holomorphic map $f$ repelling towards the domains.  
9.11  Rafael Potrie (Uruguai) Robust dynamics, invariant structures and topological classification Resumo: This text is about geometric structures imposed by robust dynamical behaviour. We explain recent results towards the classification of partially hyperbolic systems in dimension 3 using the theory of foliations and its interaction with topology. We also present recent examples which introduce a challenge in the classification program and we propose some steps to continue this classification. Finally, we give some suggestions on what to do after classification is achieved.  
9.12  Andres Koropecki (Brasil) e Meysam Nassiri (Irã) Boundary dynamics for surface homeomorphisms Resumo: We discuss some aspects of the topological dynamics of surface homeomorphisms. In particular, we survey recent results about the dynamics on the boundary of invariant domains, its relationship with the induced dynamics in the prime ends compactification, and its applications in the areapreserving setting following our recent works with P. Le Calvez.  
4.12  9.13  Serge Cantat (França) Automorphisms and dynamics: A list of open problems Resumo: Holomorphic diffeomorphisms of K3 surfaces have nice dynamical properties. I will survey the main theorems concerning their dynamical behavior: most of them were proved during the past twenty years, and many open questions remain. This will be a mix of algebraic geometry, dynamical systems, with some real algebraic geometry on the way. 
3.9  9.14  Miguel Walsh (Argentina) Characteristic subsets and the polynomial method Resumo: We provide an informal discussion of the polynomial method. This is a tool of general applicability that can be used to exploit the algebraic structure arising in some problems of arithmetic nature. 
10.10  9.15  Stéphane Nonnenmacher (França) Resonances in hyperbolic dynamics Resumo: The study of wave propagation outside bounded obstacles uncovers the existence of resonances for the Laplace operator, which are complexvalued generalized eigenvalues, relevant to estimate the long time asymptotics of the wave. In order to understand distribution of these resonances at high frequency, we employ semiclassical tools, which leads to considering the classical scattering problem, and in particular the set of trapped trajectories. We focus on “chaotic” situations, where this set is a hyperbolic repeller, generally with a fractal geometry. In this context, we derive fractal Weyl upper bounds for the resonance counting; we also obtain dynamical criteria ensuring the presence of a resonance gap. We also address situations where the trapped set is a normally hyperbolic submanifold, a case which can help analyzing the long time properties of (classical) Anosov contact flows through semiclassical methods. 
8.15  9.16  Lewis Bowen (EUA) A brief introduction to sofic entropy theory Resumo: Sofic entropy theory is a generalization of the classical Kolmogorov–Sinai entropy theory to actions of a large class of nonamenable groups called sofic groups. This is a short introduction with a guide to the literature. 
11.11  9.17  Carlangelo Liverani (Itália) Transport in partially hyperbolic fastslow systems Resumo: I will discuss, from a dynamical systems point of view, some recent attempts to rigorously derive the macroscopic laws of transport (e.g. the heat equation) from deterministic microscopic dynamics. 
11.12  9.18  Konstantin Khanin (Canadá) Renormalization and rigidity Resumo: The ideas of renormalization was introduced into dynamics around 40 years ago. By now renormalization is one of the most powerful tools in the asymptotic analysis of dynamical systems. In this article we discuss the main conceptual features of the renormalization approach, and present a selection of recent results. We also discuss open problems and formulate related conjectures. 
10.1  Colin Guillarmou (França) Analytic tools for the study of flows and inverse problems Resumo: In this survey, we review recent results in hyperbolic dynamical systems and in geometric inverse problems using analytic tools, based on spectral theory and microlocal methods.  
10.2  JeanMarc Delort (França) Long time existence results for solutions of water waves equations Resumo: We present in this talk various results, obtained during the last years by several authors, about the problem of long time existence of solutions of water waves and related equations, with initial data that are small, smooth, and decaying at infinity. After recalling some facts about local existence theory, we shall focus mainly on global existence theorems for gravity waves equations proved by Ionescu–Pusateri, Alazard–Delort and Ifrim–Tataru. We shall describe some of the ideas of the proofs of these theorems, and mention as well related results.  
8.3  10.3  Guido De Philippis (Itália) On the structure of measures constrained by linear PDEs Resumo: The aim of this note is to present some recent results on the structure of the singular part of measures satisfying a PDE constraint and to describe some applications. 
10.4  Mohamed Majdoub (Arábia Saudita) Wellposedness, global existence and decay estimates for the heat equation with general powerexponential nonlinearities Resumo: In this paper we consider the problem: $\partial_{t} u \Delta u=f(u),\; u(0)=u_0\in \exp L^p(\mathbb{R}^N),$ where $p>1$ and $f : \mathbb{R}\to\mathbb{R}$ having an exponential growth at infinity with $f(0)=0.$ We prove local wellposedness in $\exp L^p_0(\mathbb{R}^N)$ for $f(u)\sim e^{u^q}$, $0\le q \leq p$, $ u\to \infty$. However, if for some $\lambda>0$, $\liminf_{s\to \infty}\left(f(s)\,{\rm{e}}^{\lambda s^p}\right)>0,$ then nonexistence occurs in $\exp L^p(\mathbb{R}^N).$ Under smallness condition on the initial data and for exponential nonlinearity $f$ such that $f(u)\sim u^{m}$ as $u\to 0,$ ${N(m1)\over 2}\geq p$, we show that the solution is global. In particular, $p1>0$ sufficiently small is allowed. Moreover, we obtain decay estimates in Lebesgue spaces for large time which depend on $m$.  
17.5  10.5  Maria Esteban (França) Symmetry and symmetry breaking: Rigidity and flows in elliptic PDEs Resumo: The issue of symmetry and symmetry breaking is fundamental in all areas of science. Symmetry is often assimilated to order and beauty while symmetry breaking is the source of many interesting phenomena such as phase transitions, instabilities, segregation, selforganization, etc. In this contribution we review a series of sharp results of symmetry of nonnegative solutions of nonlinear elliptic differential equation associated with minimization problems on Euclidean spaces or manifolds. Nonnegative solutions of those equations are unique, a property that can also be interpreted as a rigidity result. The method relies on linear and nonlinear flows which reveal deep and robust properties of a large class of variational problems. Local results on linear instability leading to symmetry breaking and the bifurcation of nonsymmetric branches of solutions are reinterpreted in a larger, global, variational picture in which our flows characterize directions of descent. 
10.6  Helena Nussenzveig Lopes (Brasil) Fluids, walls and vanishing viscosity Resumo: The vanishing viscosity problem consists of understanding the limit, or limits, of solutions of the Navier–Stokes equations, with viscosity $\nu$, as $\nu$ tends to zero. The Navier–Stokes equations are a model for realworld fluids and the parameter $\nu$ represents the ratio of friction, or resistance to shear, and inertia. Ultimately, the relevant question is whether a realworld fluid with very small viscosity can be approximated by an ideal fluid, which has no viscosity. In this talk we will be primarily concerned with the classical open problem of the vanishing viscosity limit of fluid flows in domains with boundary. We will explore the difficulty of this problem and present some known results. We conclude with a discussion of criteria for the vanishing viscosity limit to be a solution of the ideal fluid equations.  
10.7  Yoshikazu Giga (Japão) On large time behavior of growth by birth and spread Resumo: This is essentially a survey paper on a large time behavior of solutions of some simple birth and spread models to describe growth of crystal surfaces. The models discussed here include levelset flow equations of eikonal or eikonalcurvature flow equations with source terms. Large time asymptotic speed called growth rate is studied. As an application, a simple proof is given for asymptotic profile of crystal grown by anisotropic eikonalcurvature flow.  
17.9  10.8  PierreEmmanuel Jabin (França) Quantitative estimates for Advective Equation with degenerate anelastic constraint Resumo: In these proceedings we are interested in quantitative estimates for advective equations with an anelastic constraint in presence of vacuum. More precisely, we derive a quantitative stability estimate and obtain the existence of renormalized solutions. Our main objective is to show the flexibility of the method introduced recently by the authors for the compressible Navier–Stokes' system. This method seems to be well adapted in general to provide regularity estimates on the density of compressible transport equations with possible vacuum state and low regularity of the transport velocity field; the advective equation with degenerate anelastic constraint considered here is another good example of that. As a final application we obtain the existence of global renormalized solution to the socalled lake equation with possibly vanishing topography. 
11.8  10.9  Clément Mouhot (Reino Unido) De Giorgi–Nash–Moser and Hörmander theories: New interplays Resumo: We report on recent results and a new line of research at the crossroad of two major theories in the analysis of partial differential equations. The celebrated De Giorgi–Nash–Moser theorem provides Hölder estimates and the Harnack inequality for uniformly elliptic or parabolic equations with rough coefficients in divergence form. The theory of hypoellipticity of Hörmander provides general “bracket” conditions for regularity of solutions to partial differential equations combining first and second order derivative operators when ellipticity fails in some directions. We discuss recent extensions of the De Giorgi–Nash–Moser theory to hypoelliptic equations of Kolmogorov (kinetic) type with rough coefficients. These equations combine a firstorder skewsymmetric operator with a secondorder elliptic operator involving derivatives in only part of the variables, and with rough coefficients. We then discuss applications to the Boltzmann and Landau equations in kinetic theory and present a program of research with some open questions. 
9.15  10.10  Stéphane Nonnenmacher (França) Analytic tools for the study of flows and inverse problems Resumo: In this survey, we review recent results in hyperbolic dynamical systems and in geometric inverse problems using analytic tools, based on spectral theory and microlocal methods. 
5.12  10.11  Eugenia Malinnikova (Noruega) e Alexander Logunov (Israel/Rússia) Quantitative propagation of smallness for solutions of elliptic equations Resumo: Let $u$ be a solution to an elliptic equation $div(A\nabla u)=0$ with Lipschitz coefficients in $\mathbb{R}^n$. Assume $u$ is bounded by $1$ in the ball $B=\{x\leq 1\}$. We show that if $u < \varepsilon$ on a set $ E \subset \frac{1}{2} B$ with positive $n$dimensional Hausdorf measure, then $$u\leq C\varepsilon^\gamma \quad \mbox{on} \quad \frac{1}{2}B$$ where $C>0, \gamma \in (0,1)$ do not depend on $u$ and depend only on $A$ and the measure of $E$. We specify the dependence on the measure of $E$ in the form of the Remez type inequality. Similar estimate holds for sets $E$ with Hausdorff dimension bigger than $n1$. For the gradients of the solutions we show that a similar propagation of smallness holds for sets of Hausdorff dimension bigger than $n1c$, where $c>0$ is a small numerical constant depending on the dimension only. 
12.14  10.12  Massimiliano Gubinelli (Alemanha) A panorama of singular SPDEs Resumo: I will review the setting and some of the recent results in the field of singular stochastic partial differential equations (SSPDEs). Since Hairer's invention of regularity structures this field has experienced a rapid development. SSPDEs are nonlinear equations with random and irregular source terms which make them illposed in classical sense. Their study involves a tight interplay between stochastic analysis, analysis of PDEs (including paradifferential calculus) and algebra. 
10.13  Nader Masmoudi (EUA) The Orr mechanism: Stability/Instability of the Couette flow for the 2D Euler dynamic Resumo: We review our works on the nonlinear asymptotic stability and instability of the Couette flow for the 2D incompressible Euler dynamic. In the fits part of the work we prove that perturbations to the Couette flow which are small in Gevrey spaces $G^s$ of class $1/s$ with $s > 1/2$ converge strongly in $L^2$ to a shear flow which is close to the Couette flow. Moreover in a well chosen coordinate system, the solution converges in the same Gevrey space to some limit profile. In a later work, we proved the existence of small perturbations in $G^s$ with $s<1/2$ such that the solution becomes large in Sobolev regularity and hence yields instability. In this note we discuss the most important physical and mathematical aspects of these two results and the key ideas of the proofs.  
10.14  Alexander Kiselev (EUA) Small scales and singularity formation in fluid dynamics Resumo: We review recent advances in understanding singularity and small scales formation in solutions of fluid dynamics equations. The focus is on the Euler and surface quasigeostrophic (SQG) equations and associated models.  
10.15  Yvan Martel (França) Interaction of solitons from the PDE point of view Resumo: We review recent results concerning the interactions of solitary waves for several universal nonlinear dispersive or wave equations. Though using quite different techniques, these results are partly inspired by classical papers based on the inverse scattering theory for integrable models.  
10.16  Diego Córdoba (Espanha) Interface dynamics for incompressible fluids: Splash and Splat singularities Resumo: In this survey I report on recent progress in the study of the dynamics of the interface in between two incompressible fluids with different characteristics. In particular I focus on the formation of Splash and Splat singularities in two different settings: Euler equations and Darcy's law. 
8.4  11.1  Yasuyuki Kawahigashi (Japão) Conformal field theory, vertex operator algebras and operator algebras Resumo: We present recent progress in theory of local conformal nets which is an operator algebraic approach to study chiral conformal field theory. We emphasize representation theoretic aspects and relations to theory of vertex operator algebras which gives a different and algebraic formulation of chiral conformal field theory. 
11.2  Alexander Belavin (Rússia) Special geometry on Calabi–Yau moduli spaces and $Q$invariant Milnor rings Resumo: The moduli spaces of Calabi–Yau (CY) manifolds are the special Kähler manifolds. The special Kähler geometry determines the lowenergy effective theory which arises in Superstring theory after the compactification on a CY manifold. For the cases, where the CY manifold is given as a hypersurface in the weighted projective space, a new procedure for computing the Kähler potential of the moduli space has been proposed by Konstantin Aleshkin and myself. The method is based on the fact that the moduli space of CY manifolds is a marginal subspace of the Frobenius manifold which arises on the deformation space of the corresponding Landau–Ginzburg superpotential. I review this approach and demonstrate its efficiency by computing the Special geometry of the 101dimensional moduli space of the quintic threefold around the orbifold point.  
6.5  11.3  Thomas Willwacher (Suíça) Little disks operads and Feynman diagrams Resumo: The little disks operads are classical objects in algebraic topology which have seen a wide range of applications in the past. For example they appear prominently in the Goodwillie–Weiss embedding calculus, which is a program to understand embedding spaces through algebraic properties of the little disks operads, and their action on the spaces of configurations of points (or disks) on manifolds. In this talk we review the recent understanding of the rational homotopy theory of the little disks operads, and how the resulting knowledge can be used to fulfil the promise of the Goodwillie–Weiss calculus, at least in the “simple” setting of long knot spaces and over the rationals. The derivations prominently use and are connected to graph complexes, introduced by Kontsevich and other authors. 
11.4  Benjamin Schlein (Suíça) Bogoliubov excitation spectrum for Bose–Einstein condensates Resumo: We consider interacting Bose gases trapped in a box $\Lambda = [0;1]^3$ in the Gross–Pitaevskii limit. Assuming the potential to be weak enough, we establish the validity of Bogoliubov's prediction for the ground state energy and the lowenergy excitation spectrum. These notes are based on a joint work with C. Boccato, C. Brennecke and S. Cenatiempo.  
11.5  Fabio Toninelli (França) $(2+1)$dimensional interface dynamics: Mixing time, hydrodynamic limit and anisotropic KPZ growth Resumo: Stochastic interface dynamics serve as mathematical models for diverse timedependent physical phenomena: the evolution of boundaries between thermodynamic phases, crystal growth, random deposition... Interesting limits arise at large spacetime scales: after suitable rescaling, the randomly evolving interface converges to the solution of a deterministic PDE (hydrodynamic limit) and the fluctuation process to a (in general nonGaussian) limit process. In contrast with the case of $(1+1)$dimensional models, there are very few mathematical results in dimension $(d+1), d\ge2$. As far as growth models are concerned, the $(2+1)$dimensional case is particularly interesting: Dietrich Wolf in 1991 conjectured the existence of two different universality classes (called KPZ and Anisotropic KPZ), with different scaling exponents. Here, we review recent mathematical results on (both reversible and irreversible) dynamics of some $(2+1)$dimensional discrete interfaces, mostly defined through a mapping to twodimensional dimer models. In particular, in the irreversible case, we discuss mathematical support and remaining open problems concerning Wolf's conjecture on the relation between the Hessian of the growth velocity on one side, and the universality class of the model on the other.  
11.6  Yuji Tachikawa (Japão) On ‘categories’ of quantum field theories Resumo: We give a rough description of the ‘categories’ formed by quantum field theories. A few recent mathematical conjectures derived from quantum field theories, some of which are now proven theorems, will be presented in this language.  
11.7  Mariya Shcherbina (Ucrânia) Transfer operator approach to 1d random band matrices Resumo: We discuss an application of the transfer operator approach to the analysis of the different spectral characteristics of 1d random band matrices (correlation functions of characteristic polynomials, density of states, spectral correlation functions). We show that when the bandwidth $W$ crosses the threshold $W=N^{1/2}$, the model has a kind of phase transition (crossover), whose nature can be explained by the spectral properties of the transfer operator.  
10.9  11.8  Clément Mouhot (Reino Unido) De Giorgi–Nash–Moser and Hörmander theories: New interplays Resumo: We report on recent results and a new line of research at the crossroad of two major theories in the analysis of partial differential equations. The celebrated De Giorgi–Nash–Moser theorem provides Hölder estimates and the Harnack inequality for uniformly elliptic or parabolic equations with rough coefficients in divergence form. The theory of hypoellipticity of Hörmander provides general “bracket” conditions for regularity of solutions to partial differential equations combining first and second order derivative operators when ellipticity fails in some directions. We discuss recent extensions of the De Giorgi–Nash–Moser theory to hypoelliptic equations of Kolmogorov (kinetic) type with rough coefficients. These equations combine a firstorder skewsymmetric operator with a secondorder elliptic operator involving derivatives in only part of the variables, and with rough coefficients. We then discuss applications to the Boltzmann and Landau equations in kinetic theory and present a program of research with some open questions. 
12.12  11.9  Claudio Landim (Brasil/França) Variational formulae for the capacity induced by secondorder elliptic differential operators Resumo: We review recent progress in potential theory of secondorder elliptic operators and on the metastable behavior of Markov processes. 
12.13  11.10  Hugo DuminilCopin (França/Suíça) Conformal field theory, vertex operator algebras and operator algebras Resumo: We present recent progress in theory of local conformal nets which is an operator algebraic approach to study chiral conformal field theory. We emphasize representation theoretic aspects and relations to theory of vertex operator algebras which gives a different and algebraic formulation of chiral conformal field theory. 
9.17  11.11  Carlangelo Liverani (Itália) Transport in partially hyperbolic fastslow systems Resumo: I will discuss, from a dynamical systems point of view, some recent attempts to rigorously derive the macroscopic laws of transport (e.g. the heat equation) from deterministic microscopic dynamics. 
9.18  11.12  Konstantin Khanin (Canadá) Renormalization and rigidity Resumo: The ideas of renormalization was introduced into dynamics around 40 years ago. By now renormalization is one of the most powerful tools in the asymptotic analysis of dynamical systems. In this article we discuss the main conceptual features of the renormalization approach, and present a selection of recent results. We also discuss open problems and formulate related conjectures. 
11.13  Rinat Kashaev (Suíça) The Teichmüller TQFT Resumo: We review our construction of the Teichmüller TQFT. We recall our volume conjecture for this TQFT and the examples for which this conjecture has been established. We end the paper with a brief review of our new formulation of the Teichmüller TQFT together with some anticipated future developments.  
11.14  Simone Warzel (Alemanha) N/A Resumo: N/A  
11.15  Philippe Di Francesco (França/EUA) Integrable combinatorics Resumo: We explore various combinatorial problems mostly borrowed from physics, that share the property of being continuously or discretely integrable, a feature that guarantees the existence of conservation laws that often make the problems exactly solvable. We illustrate this with: random surfaces, lattice models, and structure constants in representation theory. 
12.1  Jason Miller (Reino Unido) Liouville quantum gravity as a metric space and a scaling limit Resumo: Over the past few decades, two natural random surface models have emerged within physics and mathematics. The first is Liouville quantum gravity, which has its roots in string theory and conformal field theory from the 1980s and 1990s. The second is the Brownian map, which has its roots in planar map combinatorics from the 1960s together with recent scaling limit results. This article surveys a series of works with Sheffield in which it is shown that Liouville quantum gravity (LQG) with parameter $\gamma=\sqrt{8/3}$ is equivalent to the Brownian map. We also briefly describe a series of works with Gwynne which use the $\sqrt{8/3}$LQG metric to prove the convergence of selfavoiding walks and percolation on random planar maps towards ${SLE}_{8/3}$ and ${SLE}_6$, respectively, on a Brownian surface.  
12.2  Paul Bourgade (EUA) Random band matrices Resumo: We survey recent mathematical results about the spectrum of random band matrices. We start by exposing the Erdős–Schlein–Yau dynamic approach, its application to Wigner matrices, and extension to other meanfield models. We then introduce random band matrices and the problem of their Anderson transition. We finally expose a method to obtain delocalization and universality in some sparse regimes, highlighting the role of quantum unique ergodicity.  
12.3  Bálint Tóth (Hungria/Reino Unido) Diffusive and superdiffusive limits for random walks and diffusions with long memory Resumo: We survey recent results of normal and anomalous diffusion of two types of random motions with long memory in $\mathbb{R}^d$ or $\mathbb{Z}^d$. The first class consists of random walks on $\mathbb{Z}^d$ in divergencefree random drift field, modelling the motion of a particle suspended in timestationary incompressible turbulent flow. The second class consists of selfrepelling random diffusions, where the diffusing particle is pushed by the negative gradient of its own occupation time measure towards regions less visited in the past. We establish normal diffusion (with squarerootoftime scaling and Gaussian limiting distribution) in three and more dimensions and typically anomalously fast diffusion in low dimensions (typically, one and two). Results are quoted from various papers published between 2012–2017, with some hints to the main ideas of the proofs. No technical details are presented here.  
12.4  Byeong Park (Coréia do Sul) Nonparametric additive regression Resumo: In this article we discuss statistical methods of estimating structured nonparametric regression models. Our discussion is mainly on the additive models where the regression function (map) is expressed as a sum of unknown univariate functions (maps), but it also covers some other non and semiparametric models. We present the state of the art in the subject area with the prospect of an extension to nonEuclidean data objects.  
12.5  Allan Sly (EUA) Transitions for random constraint satisfaction problems Resumo: N/A  
17.6  12.6  Josselin Garnier (França) Multiscale analysis of wave propagation in random media Resumo: Wave propagation in random media can be studied by multiscale and stochastic analysis. We review some recent advances and their applications. In particular, in a physically relevant regime of separation of scales, wave propagation is governed by a Schrödingertype equation driven by a Brownian field. We study the associated moment equations and describe the propagation of coherent and incoherent waves. We quantify the scintillation of the wave and the fluctuations of the Wigner distribution. These results make it possible to introduce and characterize correlationbased imaging methods. 
17.7  12.7  Sem Borst (Holanda) Scalable load balancing in networked systems: Universality properties and stochastic coupling methods Resumo: We present an overview of scalable load balancing algorithms which provide favorable delay performance in largescale systems, and yet only require minimal implementation overhead. Aimed at a broad audience, the paper starts with an introduction to the basic load balancing scenario – referred to as the supermarket model – consisting of a single dispatcher where tasks arrive that must immediately be forwarded to one of $N$ singleserver queues. The supermarket model is a dynamic counterpart of the classical ballsandbins setup where balls must be sequentially distributed across bins. A popular class of load balancing algorithms are powerof$d$ or JSQ($d$) policies, where an incoming task is assigned to a server with the shortest queue among $d$ servers selected uniformly at random. As the name reflects, this class includes the celebrated JointheShortestQueue (JSQ) policy as a special case ($d = N$), which has strong stochastic optimality properties and yields a mean waiting time that vanishes as $N$ grows large for any fixed subcritical load. However, a nominal implementation of the JSQ policy involves a prohibitive communication burden in largescale deployments. In contrast, a simple random assignment policy ($d = 1$) does not entail any communication overhead, but the mean waiting time remains constant as $N$ grows large for any fixed positive load. In order to examine the fundamental tradeoff between delay performance and implementation overhead, we consider an asymptotic regime where the diversity parameter $d(N)$ depends on $N$. We investigate what growth rate of $d(N)$ is required to match the optimal performance of the JSQ policy on fluid and diffusion scale, and achieve a vanishing waiting time in the limit. The results demonstrate that the asymptotics for the JSQ($d(N)$) policy are insensitive to the exact growth rate of $d(N)$, as long as the latter is sufficiently fast, implying that the optimality of the JSQ policy can asymptotically be preserved while dramatically reducing the communication overhead. Stochastic coupling techniques play an instrumental role in establishing the asymptotic optimality and universality properties, and augmentations of the coupling constructions allow these properties to be extended to infiniteserver settings and network scenarios. We additionally show how the communication overhead can be reduced yet further by the socalled JointheIdleQueue (JIQ) scheme, leveraging memory at the dispatcher to keep track of idle servers. 
8.7  12.8  Dmitry Chelkak (França/Rússia) Planar Ising model at criticality: Stateoftheart and perspectives Resumo: In this essay, we briefly discuss recent developments, started a decade ago in the seminal work of Smirnov and continued by a number of authors, centered around the conformal invariance of the critical planar Ising model on $\mathbb{Z}^2$ and, more generally, of the critical Zinvariant Ising model on isoradial graphs (rhombic lattices). We also introduce a new class of embeddings of general weighted planar graphs (sembeddings), which might, in particular, pave the way to true universality results for the planar Ising model. 
12.9  Jonathan Taylor (EUA) A selective survey of selective inference Resumo: It is not difficult to find stories of a crisis in modern science, either in the popular press or in the scientific literature. There are likely multiple sources for this crisis. It is also well documented that one source of this crisis is the misuse of statistical methods in science, with the $P$value receiving its fair share of criticism. It could be argued that this misuse of statistical methods is caused by a shift in how data is used in 21st century science compared to its use in the mid20th century which presumed scientists had formal statistical hypotheses before collecting data. With the advent of sophisticated statistical software available to anybody this paradigm has been shifted to one in which scientists collect data first and ask questions later.  
12.10  Elizaveta Levina (EUA) Liouville quantum gravity as a metric space and a scaling limit Resumo: Over the past few decades, two natural random surface models have emerged within physics and mathematics. The first is Liouville quantum gravity, which has its roots in string theory and conformal field theory from the 1980s and 1990s. The second is the Brownian map, which has its roots in planar map combinatorics from the 1960s together with recent scaling limit results. This article surveys a series of works with Sheffield in which it is shown that Liouville quantum gravity (LQG) with parameter $\gamma=\sqrt{8/3}$ is equivalent to the Brownian map. We also briefly describe a series of works with Gwynne which use the $\sqrt{8/3}$LQG metric to prove the convergence of selfavoiding walks and percolation on random planar maps towards ${SLE}_{8/3}$ and ${SLE}_6$, respectively, on a Brownian surface.  
12.11  Noureddine El Karoui (EUA) Random matrices and highdimensional statistics: Beyond covariance matrices Resumo: The last twentyorso years have seen spectacular progress in our understanding of the fine spectral properties of largedimensional random matrices. These results have also shown light on the behavior of various statistical estimators used in multivariate statistics. In this short note, we will describe new strands of results, which show that intuition and techniques built on the theory of random matrices and concentration of measure ideas shed new light and bring to the fore new ideas about an arguably even more important set of statistical tools, namely Mestimators and certain bootstrap methods. All the results are obtained in the large $n$, large $p$ setting, where both the number of observations and the number of predictors go to infinity.  
11.9  12.12  Claudio Landim (Brasil/França) Variational formulae for the capacity induced by secondorder elliptic differential operators Resumo: We review recent progress in potential theory of secondorder elliptic operators and on the metastable behavior of Markov processes. 
11.10  12.13  Hugo DuminilCopin (França/Suíça) Sixty years of percolation Resumo: Percolation models describe the inside of a porous material. The theory emerged timidly in the middle of the twentieth century before becoming one of the major objects of interest in probability and mathematical physics. The golden age of percolation is probably the eighties, during which most of the major results were obtained for the most classical of these models, named Bernoulli percolation, but it is really the two following decades which put percolation theory at the crossroad of several domains of mathematics. In this broad review, we propose to describe briefly some recent progress as well as some famous challenges remaining in the field. This review is not intended to probabilists (and a fortiori not to specialists in percolation theory): the target audience is mathematicians of all kinds. 
10.12  12.14  Massimiliano Gubinelli (Alemanha) A panorama of singular SPDEs Resumo: I will review the setting and some of the recent results in the field of singular stochastic partial differential equations (SSPDEs). Since Hairer's invention of regularity structures this field has experienced a rapid development. SSPDEs are nonlinear equations with random and irregular source terms which make them illposed in classical sense. Their study involves a tight interplay between stochastic analysis, analysis of PDEs (including paradifferential calculus) and algebra. 
13.11  12.15  Richard Kenyon (EUA) Limit shapes and their analytic parameterizations Resumo: A “limit shape” is a form of the law of large numbers, and happens when a large random system, typically consisting of many interacting particles, can be described, after an appropriate normalization, by a certain nonrandom object. Limit shapes occur in, for example, random integer partitions or in random interface models such as the dimer model. Typically limit shapes can be described by some variational formula based on a large deviations estimate. We discuss limit shapes for certain 2dimensional interface models, and explain how their underlying analytic structure is related to a (conjectural in some cases) conformal invariance property for the models 
12.16  Andrea Montanari (EUA) Mean field asymptotics in highdimensional statistics: From exact results to efficient algorithms Resumo: Modern data analysis challenges require building complex statistical models with massive numbers of parameters. It is nowadays commonplace to learn models with millions of parameters by using iterative optimization algorithms. What are typical properties of the estimated models? In some cases, the highdimensional limit of a statistical estimator is analogous to the thermodynamic limit of a certain (disordered) statistical mechanics system. Building on mathematical ideas from the meanfield theory of disordered systems, exact asymptotics can be computed for highdimensional statistical learning problems. This theory suggests new practical algorithms and new procedures for statistical inference. Also, it leads to intriguing conjectures about the fundamental computational limits for statistical estimation.  
12.17  Peter Bühlmann (Suíça) Invariance in heterogeneous, largescale and highdimensional data Resumo: Statistical inference from largescale data can benefit from sources of heterogeneity. We discuss recent progress of the mathematical formalization and theory for exploiting heterogeneity towards predictive stability and causal inference in highdimensional models. The topic is directly motivated by a broad range of applications and we will show an illustration from molecular biology with gene knock out experiments.  
12.18  Vladimir Koltchinskii (EUA) Asymptotic efficiency in highdimensional covariance estimation Resumo: We discuss recent results on asymptotically efficient estimation of smooth functionals of covariance operator $\Sigma$ of a mean zero Gaussian random vector $X$ in a separable Hilbert space based on $n$ i.i.d. observations of this vector. We are interested in functionals that are of importance in highdimensional statistics such as linear forms of eigenvectors of $\Sigma$ (principal components) as well as in more general functionals of the form $\langle f(\Sigma),B\rangle,$ where $f:{\mathbb R}\mapsto {\mathbb R}$ is a sufficiently smooth function and $B$ is an operator with nuclear norm bounded by a constant. In the case when $X$ takes values in a finitedimensional space of dimension $d\leq n^{\alpha}$ for some $\alpha \in (0,1)$ and $f$ belongs to Besov space $B^{s}_{\infty,1}({\mathbb R})$ for $s>\frac{1}{1\alpha},$ we develop asymptotically normal estimators of $\langle f(\Sigma),B\rangle$ with $\sqrt{n}$ convergence rate and prove asymptotic minimax lower bounds showing their asymptotic efficiency. 
3.1  13.1  Maryna Viazovska (Suíça) Sharp sphere packings Resumo: In this talk we will speak about recent progress on the sphere packing problem. The packing problem can be formulated for a wide class of metric spaces equipped with a measure. An interesting feature of this optimization problem is that a slight change of parameters (such as the dimension of the space or radius of the spheres) can dramatically change the properties of optimal configurations. We will focus on those cases when the solution of the packing problem is particularly simple. Namely, we say that a packing problem is sharp if its density attains the socalled linear programming bound. Several such configurations have been known for a long time and we have recently proved that the $E_8$ lattice sphere packing in $\mathbb{R}^8$ and the Leech lattice packing in $\mathbb{R}^{24}$ are sharp. Moreover, we will discuss common unusual properties of shared by such configurations and outline possible applications to Fourier analysis. 
13.2  Alexander Postnikov (EUA) Positive Grassmannian and polyhedral subdivisions Resumo: The nonnegative Grassmannian is a cell complex with rich geometric, algebraic, and combinatorial structures. Its study involves interesting combinatorial objects, such as positroids and plabic graphs. Remarkably, the same combinatorial structures appeared in many other areas of mathematics and physics, e.g., in the study of cluster algebras, scattering amplitudes, and solitons. We discuss new ways to think about these structures. In particular, we identify plabic graphs and more general Grassmannian graphs with polyhedral subdivisions induced by 2dimensional projections of hypersimplices. This implies a close relationship between the positive Grassmannian and the theory of fiber polytopes and the generalized Baues problem. This suggests natural extensions of objects related to the positive Grassmannian.  
13.3  Gábor Tardos (Hungria) Extremal theory of ordered graphs Resumo: We call simple graphs with a linear order on the vertices ordered graphs. Turántype extremal graph theory naturally extends to ordered graphs. This is a survey on the ongoing research in the extremal theory of ordered graphs with an emphasis on open problems.  
13.4  László Babai (EUA) Group, graphs, algorithms: The Graph Isomorphism Problem Resumo: Graph Isomorphism (GI) is one of a small number of natural algorithmic problems with unsettled complexity status in the $P/NP$ theory: not expected to be $NP$complete, yet not known to be solvable in polynomial time. Arguably, the GI problem boils down to filling the gap between symmetry and regularity, the former being defined in terms of automorphisms, the latter in terms of equations satisfied by numerical parameters. Recent progress on the complexity of GI relies on a combination of the asymptotic theory of permutation groups and asymptotic properties of highly regular combinatorial structures called coherent configurations. Group theory provides the tools to infer either global symmetry or global irregularity from local information, eliminating the symmetry/regularity gap in the relevant scenario; the resulting global structure is the subject of combinatorial analysis. These structural studies are melded in a divideandconquer algorithmic framework pioneered in the GI context by Eugene M. Luks (1980).  
13.5  June Huh (EUA) Combinatorial applications of the Hodge–Riemann relations Resumo: Why do natural and interesting sequences often turn out to be logconcave? We give one of many possible explanations, from the viewpoint of “standard conjectures”. We illustrate with several examples from combinatorics.  
13.6  József Balogh (EUA) e Robert Morris (Brasil) The method of hypergraph containers Resumo: In this survey we describe a recentlydeveloped technique for bounding the number (and controlling the typical structure) of finite objects with forbidden substructures. This technique exploits a subtle clustering phenomenon exhibited by the independent sets of uniform hypergraphs whose edges are sufficiently evenly distributed; more precisely, it provides a relatively small family of ‘containers’ for the independent sets, each of which contains few edges. We attempt to convey to the reader a general highlevel overview of the method, focusing on a small number of illustrative applications in areas such as extremal graph theory, Ramsey theory, additive combinatorics, and discrete geometry, and avoiding technical details as much as possible.  
13.7  Nicholas Wormald (Austrália) Asymptotic enumeration of graphs with given degree sequence Resumo: We survey results on counting graphs with given degree sequence, focusing on asymptotic results, and mentioning some of the applications of these results. The main recent development is the proof of a conjecture that facilitates access to the degree sequence of a random graph via a model incorporating independent binomial random variables. The basic method used in the proof was to examine the changes in the counting function when the degrees are perturbed. We compare with several previous uses of this type of method.  
13.8  Balázs Szegedy (Hungria) From graph limits to higher order Fourier analysis Resumo: The socalled graph limit theory is an emerging diverse subject at the meeting point of many different areas of mathematics. It enables us to view finite graphs as approximations of often more perfect infinite objects. In this survey paper we tell the story of some of the fundamental ideas in structural limit theories and how these ideas led to a general algebraic approach (the nilspace approach) to higher order Fourier analysis.  
13.9  Igor Pak (EUA) Complexity problems in enumerative combinatorics Resumo: We give a broad survey of recent results in enumerative combinatorics and their complexity aspects.  
13.10  Peter Keevash (Reino Unido) Sharp sphere packings Resumo: In this talk we will speak about recent progress on the sphere packing problem. The packing problem can be formulated for a wide class of metric spaces equipped with a measure. An interesting feature of this optimization problem is that a slight change of parameters (such as the dimension of the space or radius of the spheres) can dramatically change the properties of optimal configurations. We will focus on those cases when the solution of the packing problem is particularly simple. Namely, we say that a packing problem is sharp if its density attains the socalled linear programming bound. Several such configurations have been known for a long time and we have recently proved that the $E_8$ lattice sphere packing in $\mathbb{R}^8$ and the Leech lattice packing in $\mathbb{R}^{24}$ are sharp. Moreover, we will discuss common unusual properties of shared by such configurations and outline possible applications to Fourier analysis.  
12.15  13.11  Richard Kenyon (EUA) Limit shapes and their analytic parameterizations Resumo: A “limit shape” is a form of the law of large numbers, and happens when a large random system, typically consisting of many interacting particles, can be described, after an appropriate normalization, by a certain nonrandom object. Limit shapes occur in, for example, random integer partitions or in random interface models such as the dimer model. Typically limit shapes can be described by some variational formula based on a large deviations estimate. We discuss limit shapes for certain 2dimensional interface models, and explain how their underlying analytic structure is related to a (conjectural in some cases) conformal invariance property for the models 
14.1  Aleksander Mądry (EUA) Gradients and flows: Continuous optimization approaches to the Maximum Flow Problem Resumo: We use the lens of the maximum flow problem, one of the most fundamental problems in algorithmic graph theory, to describe a new framework for design of graph algorithms. At a high level, this framework casts the graph problem at hand as a convex optimization task and then applies to it an appropriate method from the continuous optimization toolkit. We survey how this new approach led to the first in decades progress on the maximum flow problem and then briefly sketch the challenges that still remain.  
14.2  Andris Ambainis (Letônia) Understanding quantum algorithms via query complexity Resumo: Query complexity is a model of computation in which we have to compute a function $f(x_1, \ldots, x_N)$ of variables $x_i$ which can be accessed via queries. The complexity of an algorithm is measured by the number of queries that it makes. Query complexity is widely used for studying quantum algorithms, for two reasons. First, it includes many of the known quantum algorithms (including Grover's quantum search and a key subroutine of Shor's factoring algorithm). Second, one can prove lower bounds on the query complexity, bounding the possible quantum advantage. In the last few years, there have been major advances on several longstanding problems in the query complexity. In this talk, we survey these results and related work, including:
 
14.3  Benjamin Rossman (Canadá) Lower bounds for subgraph isomorphism Resumo: We consider the problem of determining whether an Erdős–Rényi random graph contains a subgraph isomorphic to a fixed pattern, such as a clique or cycle of constant size. The computational complexity of this problem is tied to fundamental open questions including $P$ vs. $NP$ and $NC^1$ vs. $L$. We give an overview of unconditional averagecase lower bounds for this problem (and its colored variant) in a few important restricted classes of Boolean circuits.  
14.4  Yael Kalai (EUA) Delegating computation via nosignaling strategies Resumo: Efficient verification of computation, also known as delegation of computation, is one of the most fundamental notions in computer science, and in particular it lies at the heart of the P vs.\ NP question. This article contains a high level overview of the evolution of proofs in computer science, and shows how this evolution is instrumental to solving the problem of delegating computation. We highlight a curious connection between the problem of delegating computation and the notion of nosignaling strategies from quantum physics.  
14.6  Prasad Raghavendra (EUA) e David Steurer (EUA) High dimensional estimation via SumofSquares Proofs Resumo: Estimation is the computational task of recovering a hidden parameter $x$ associated with a distribution $\mathcal{D}_x$, given a measurement $y$ sampled from the distribution. High dimensional estimation problems can be formulated as system of polynomial equalities and inequalities, and thus give rise to natural probability distributions over polynomial systems. Sum of squares proofs not only provide a powerful framework to reason about polynomial systems, but they are constructive in that there exist efficient algorithms to search for sumofsquares proofs. The efficiency of these algorithms degrade exponentially in the degree of the sumofsquares proofs. Understanding and characterizing the power of sumofsquares proofs for estimation problems has been a subject of intense study in recent years. On one hand, there is a growing body of work utilizing sumofsquares proofs for recovering solutions to polynomial systems whenever the system is feasible. On the ot  
14.7  Piotr Indyk (EUA) Approximate nearest neighbor search in high dimensions Resumo: The nearest neighbor problem is defined as follows: Given a set $P$ of $n$ points in some metric space $(X,\mathsf{D})$, build a data structure that, given any point $q$, returns a point in $P$ that is closest to $q$ (its “nearest neighbor” in $P$). The data structure stores additional information about the set $P$, which is then used to find the nearest neighbor without computing all distances between $q$ and $P$. The problem has a wide range of applications in machine learning, computer vision, databases and other fields. To reduce the time needed to find nearest neighbors and the amount of memory used by the data structure, one can formulate the approximate nearest neighbor problem, where the the goal is to return any point $p' \in P$ such that the distance from $q$ to $p'$ is at most $c \cdot \min_{p \in P} \mathsf{D}(q,p)$, for some $c\ge 1$. Over the last two decades many efficient solutions to this problem were developed. In this article we survey these developments, as well as their connections to questions in geometric functional analysis and combinatorial geometry.  
14.8  Virginia Vassilevska Williams (EUA) On some finegrained questions in algorithms and complexity Resumo: In recent years, a new “finegrained” theory of computational hardness has been developed, based on “finegrained reductions” that focus on exact running times for problems. Mimicking NPhardness, the approach is to (1) select a key problem X that for some function $t$, is conjectured to not be solvable by any $O(t(n)^{1\epsilon})$ time algorithm for $\epsilon>0$, and (2) reduce X in a finegrained way to many important problems, thus giving tight conditional time lower bounds for them. This approach has led to the discovery of many meaningful relationships between problems, and to equivalence classes. The main key problems used to base hardness on have been: the $3$SUM problem, the CNFSAT problem (based on the Strong Exponential Time Hypothesis (SETH)) and the All Pairs Shortest Paths Problem. Research on SETHbased lower bounds has flourished in particular in recent years showing that the classical algorithms are optimal for problems such as Approximate Diameter, Edit Distance, Frechet Distance and Longest Common Subsequence. This paper surveys the current progress in this area, and highlights some exciting new developments.  
14.9  Neeraj Kayal (Índia) N/A Resumo: N/A 
17.1  15.1  Manuel Castro (Espanha) A review on high order wellbalanced pathconservative finite volume schemes for geophysical flows Resumo: In this work a general strategy to design high order wellbalanced schemes for hyperbolic system with nonconservative products and/or source terms is reviewed. We briefly recall the theory of Dal Maso–LeFloch–Murat to define weak solutions of nonconservative systems and how it has been used to establish the notion of pathconservative schemes. Next, a family of high order finite volume methods combining a reconstruction operator and a first order pathconservative scheme is described. Then, the wellbalanced property of the proposed methods is analyzed. Finally, some challenging examples on tsunami modeling are shown. 
17.2  15.2  Qiang Du (EUA) An invitation to nonlocal modeling, analysis and computation Resumo: This lecture serves as an invitation to further studies on nonlocal models, their mathematics, computation, and applications. We sample our recent attempts in the development of a systematic mathematical framework for nonlocal models, including basic elements of nonlocal vector calculus, wellposedness of nonlocal variational problems, coupling to local models, convergence and compatibility of numerical approximations, and applications to nonlocal mechanics and diffusion. We also draw connections with traditional models and other relevant mathematical subjects. 
17.3  15.3  Raimund Bürger (Chile) Convectiondiffusionreaction and transportflow problems motivated by models of sedimentation: Some recent advances Resumo: The sedimentation of a suspension is a unit operation widely used in mineral processing, chemical engineering, wastewater treatment, and other industrial applications. Mathematical models that describe these processes and may be employed for simulation, design and control are usually given as nonlinear, timedependent partial differential equations that in one space dimension include strongly degenerate convectiondiffusionreaction equations with discontinuous coefficients, and in two or more dimensions, coupled flowtransport problems. These models incorporate nonstandard properties that have motivated original research in applied mathematics and numerical analysis. This contribution summarizes recent advances, and presents original numerical results, for three different topics of research: a novel method of flux identification for a scalar conservation law from observation of curved shock trajectories that can be observed in sedimentation in a cone; a new description of continuous sedimentation with reactions including transport and reactions of biological components; and the numerical solution of a multidimensional sedimentationconsolidation system by an augmented mixedprimal method, including an a posteriori error estimation. 
17.4  15.4  Shi Jin (China/EUA) Mathematical analysis and numerical methods for multiscale kinetic equations with uncertainties Resumo: Kinetic modeling and computation face the challenges of multiple scales and uncertainties. Developing efficient multiscale computational methods, and quantifying uncertainties arising in their collision kernels or scattering coefficients, initial or boundary data, forcing terms, geometry, etc. have important engineering and industrial applications. In this article we will report our recent progress in the study of multiscale kinetic equations with uncertainties modelled by random inputs. We first study the mathematical properties of uncertain kinetic equations, including their regularity and longtime behavior in the random space, and sensitivity of their solutions with respect to the input and scaling parameters. Using the hypocoercivity of kinetic operators, we provide a general framework to study these mathematical properties for general class of linear and nonlinear kinetic equations in various asymptotic regimes. We then approximate these equations in random space by the stochastic Galerkin methods, study the numerical accuracy and longtime behavior of the methods, and furthermore, make the methods “stochastically asymptotic preserving”, in order to handle the multiple scales efficiently. 
15.5  AnnaKarin Tornberg (Suécia) FFT based spectral Ewald methods as an alternative to fast multipole methods Resumo: In this paper, we review a set of fast and spectrally accurate methods for rapid evaluation of three dimensional electrostatic and Stokes potentials. The algorithms use the socalled Ewald decomposition and are FFTbased, which makes them naturally most efficient for the triply periodic case. Two key ideas have allowed efficient extension of these Spectral Ewald (SE) methods to problems with periodicity in only one or two dimensions: an adaptive 3D FFT that apply different upsampling rates locally combined with a new method for FFT based solutions of free space harmonic and biharmonic problems. The latter approach is also used to extend to the free space case, with no periodicity. For the nonradial kernels of Stokes flow, the structure of their Fourier transform is exploited to extend the applicability from the radial harmonic and biharmonic kernels. A window function is convolved with the point charges to assign values on the FTT grid. Spectral accuracy is attained with a variable number of points in the support of the window function, tuning a shape parameter according to this choice. A new window function, recently introduced in the context of a nonuniform FFT algorithm, allows for further reduction in the computational time as compared to the truncated Gaussians previously used in the SE method.  
15.6  Barbara Wohlmuth (Alemanha) N/A Resumo: N/A  
15.7  Michael Giles (Reino Unido) An introduction to multilevel Monte Carlo methods Resumo: In recent years there has been very substantial growth in stochastic modelling in many application areas, and this has led to much greater use of Monte Carlo methods to estimate expected values of output quantities from stochastic simulation. However, such calculations can be expensive when the cost of individual stochastic simulations is very high. Multilevel Monte Carlo greatly reduces the computational cost by performing most simulations with low accuracy at a correspondingly low cost, with relatively few being performed at high accuracy and a high cost. This article reviews the key ideas behind the multilevel Monte Carlo method. Some applications are discussed to illustrate the flexibility and generality of the approach, and the challenges in its numerical analysis.  
15.8  Pingwen Zhang (China) Numerical mathematics of quasicrystals Resumo: Quasicrystals are one kind of fascinating aperiodic structures, and give a strong impact on material science, solid state chemistry, condensed matter physics and soft matters. The theory of quasicrystals, included in aperiodic order, has grown rapidly in mathematical and physical areas over the past few decades. Many scientific problems have been explored with the efforts of physicists and mathematicians. However, there are still lots of open problems which might to be solved by the close collaboration of physicists, mathematicians and computational mathematicians. In this article, we would like to bridge the physical quasicrystals and mathematical quasicrystals from the perspective of numerical mathematics.  
15.9  Siddhartha Mishra (Suíça) On the convergence of numerical schemes for hyperbolic systems of conservation laws Resumo: A large variety of efficient numerical methods, of the finite volume, finite difference and DG type, have been developed for approximating hyperbolic systems of conservation laws. However, very few rigorous convergence results for these methods are available. We survey the state of the art on this crucial question of numerical analysis by summarizing classical results of convergence to entropy solutions for scalar conservation laws. Very recent results on convergence of ensemble Monte Carlo methods to the measurevalued and statistical solutions of multidimensional systems of conservation laws are also presented.  
15.10  Tao Tang (China) A review on high order wellbalanced pathconservative finite volume schemes for geophysical flows Resumo: In this work a general strategy to design high order wellbalanced schemes for hyperbolic system with nonconservative products and/or source terms is reviewed. We briefly recall the theory of Dal Maso–LeFloch–Murat to define weak solutions of nonconservative systems and how it has been used to establish the notion of pathconservative schemes. Next, a family of high order finite volume methods combining a reconstruction operator and a first order pathconservative scheme is described. Then, the wellbalanced property of the proposed methods is analyzed. Finally, some challenging examples on tsunami modeling are shown. 
16.1  Emmanuel Trélat (França) Optimal shape and location of sensors or actuators in PDE models Resumo: We report on a series of works done in collaboration with Y. Privat and E. Zuazua, concerning the problem of optimizing the shape and location of sensors and actuators for systems whose evolution is driven by a linear partial differential equation. This problem is frequently encountered in applications where one wants to optimally design sensors in order to maximize the quality of the reconstruction of solutions by using only partial observations, or to optimally design actuators in order to control a given process with minimal efforts. For example, we model and solve the following informal question: what is the optimal shape and location of a thermometer? Note that we want to optimize not only the placement but also the shape of the observation or control subdomain over the class of all possible measurable subsets of the domain having a prescribed Lebesgue measure. By probabilistic considerations we model this optimal design problem as the one of maximizing a spectral functional interpreted as a randomized observability constant, which models optimal observabnility for random initial data. Solving this problem strongly depends on the operator in the PDE model and requires fine knowledge on the asymptotic properties of eigenfunctions of that operator. For parabolic equations like heat, Stokes or anomalous diffusion equations, we prove the existence and uniqueness of a best domain, proved to be regular enough, and whose algorithmic construction depends in general on a finite number of modes. In contrast, for wave or Schrödinger equations, relaxation may occur and our analysis reveals intimate relations with quantum chaos, more precisely with quantum ergodicity properties of the Laplacian eigenfunctions.  
16.2  Jean Lasserre (França) The momentSOS hierarchy Resumo: The MomentSOS hierarchy initially introduced in optimization in 2000, is based on the theory of the $\mathbf{K}$moment problem and its dual counterpart, polynomials that are positive on $\mathbf{K}$. It turns out that this methodology can be also applied to solve problems with positivity constraints “$f(\mathbf{x})\geq0$ for all $\mathbf{x}\in\mathbf{K}$” and/or linear constraints on Borel measures. Such problems can be viewed as specific instances of the “Generalized Problem of Moments” (GPM) whose list of important applications in various domains is endless. We describe this methodology and outline some of its applications in various domains.  
16.3  Matti Lassas (Finlândia) Inverse problems for linear and nonlinear hyperbolic equations Resumo: We consider inverse problems for hyperbolic equations and systems and the solutions of these problems based on the focusing of waves. Several inverse problems for linear equations can be solved using control theory. When the coefficients of the modelling equation are unknown, the construction of the point sources requires solving blind control problems. For nonlinear equations we consider a new artificial point source method that applies the nonlinear interaction of waves to create microlocal points sources inside the unknown medium. The novel feature of this method is that it utilizes the nonlinearity as a tool in imaging, instead of considering it as a difficult perturbation of the system. To demonstrate the method, we consider the nonlinear wave equation and the coupled Einstein and scalar field equations.  
16.4  Claudia Sagastizábal (Brasil) A $\mathcal{VU}$point of view of nonsmooth optimization Resumo: The realization that many nondifferentiable functions exhibit some form of structured nonsmoothness has been atracting the efforts of many researchers in the last decades. Identifying theoretically and computationally certain manifolds where a nonsmooth function behaves smoothly poses challenges for the nonsmooth optimization community. We review a sequence of milestones in the area that led to the development of algorithms of the bundle type that can track the region of smoothnes and mimic a Newton algorithm to converge with superlinear speed. The new generation of bundle methods is sufficiently versatile to deal with structured objective functions, even when the available information is inexact.  
16.5  Philippe Toint (Bélgica) Worstcase evaluation complexity and optimality of secondorder methods for nonconvex smooth optimization Resumo: We establish or refute the optimality of inexact secondorder methods for unconstrained nonconvex optimization from the point of view of worstcase evaluation complexity, improving and generalizing our previous results. To this aim, we consider a new general class of inexact secondorder algorithms for unconstrained optimization that includes regularization and trustregion variations of Newton's method as well as of their linesearch variants. For each method in this class and arbitrary accuracy threshold $\epsilon \in (0,1)$, we exhibit a smooth objective function with bounded range, whose gradient is globally Lipschitz continuous and whose Hessian is $\alpha$Hölder continuous (for given $\alpha \in [0,1]$), for which the method in question takes at least $\lfloor\epsilon^{(2+\alpha)/(1+\alpha)}\rfloor$ function evaluations to generate a first iterate whose gradient is smaller than $\epsilon$ in norm. Moreover, we also construct another function on which Newton's takes $\lfloor\epsilon^{2}\rfloor$ evaluations, but whose Hessian is Lipschitz continuous on the path of iterates. These examples provide lower bounds on the worstcase evaluation complexity of methods in our class when applied to smooth problems satisfying the relevant assumptions. Furthermore, for $\alpha=1$, this lower bound is of the same order in $\epsilon$ as the upper bound on the worstcase evaluation complexity of the cubic regularization method and other algorithms in a class of methods recently proposed by Curtis, Robinson and Samadi or by Royer and Wright, thus implying that these methods have optimal worstcase evaluation complexity within a wider class of secondorder methods, and that Newton's method is suboptimal.  
16.6  Rekha Thomas (EUA) Spectrahedral lifts of convex sets Resumo: Efficient representations of convex sets are of crucial importance for many algorithms that work with them. It is wellknown that sometimes, a complicated convex set can be expressed as the projection of a much simpler set in higher dimensions called a lift of the original set. This is a brief survey of recent developments in the topic of lifts of convex sets. Our focus will be on lifts that arise from affine slices of real positive semidefinite cones known as psd or spectrahedral lifts. The main result is that projection representations of a convex set are controlled by factorizations, through closed convex cones, of an operator that comes from the convex set. This leads to several research directions and results that lie at the intersection of convex geometry, combinatorics, real algebraic geometry, optimization, computer science and more. 
15.1  17.1  Manuel Castro (Espanha) A review on high order wellbalanced pathconservative finite volume schemes for geophysical flows Resumo: In this work a general strategy to design high order wellbalanced schemes for hyperbolic system with nonconservative products and/or source terms is reviewed. We briefly recall the theory of Dal Maso–LeFloch–Murat to define weak solutions of nonconservative systems and how it has been used to establish the notion of pathconservative schemes. Next, a family of high order finite volume methods combining a reconstruction operator and a first order pathconservative scheme is described. Then, the wellbalanced property of the proposed methods is analyzed. Finally, some challenging examples on tsunami modeling are shown. 
15.2  17.2  Qiang Du (EUA) An invitation to nonlocal modeling, analysis and computation Resumo: This lecture serves as an invitation to further studies on nonlocal models, their mathematics, computation, and applications. We sample our recent attempts in the development of a systematic mathematical framework for nonlocal models, including basic elements of nonlocal vector calculus, wellposedness of nonlocal variational problems, coupling to local models, convergence and compatibility of numerical approximations, and applications to nonlocal mechanics and diffusion. We also draw connections with traditional models and other relevant mathematical subjects. 
15.3  17.3  Raimund Bürger (Chile) Convectiondiffusionreaction and transportflow problems motivated by models of sedimentation: Some recent advances Resumo: The sedimentation of a suspension is a unit operation widely used in mineral processing, chemical engineering, wastewater treatment, and other industrial applications. Mathematical models that describe these processes and may be employed for simulation, design and control are usually given as nonlinear, timedependent partial differential equations that in one space dimension include strongly degenerate convectiondiffusionreaction equations with discontinuous coefficients, and in two or more dimensions, coupled flowtransport problems. These models incorporate nonstandard properties that have motivated original research in applied mathematics and numerical analysis. This contribution summarizes recent advances, and presents original numerical results, for three different topics of research: a novel method of flux identification for a scalar conservation law from observation of curved shock trajectories that can be observed in sedimentation in a cone; a new description of continuous sedimentation with reactions including transport and reactions of biological components; and the numerical solution of a multidimensional sedimentationconsolidation system by an augmented mixedprimal method, including an a posteriori error estimation. 
15.4  17.4  Shi Jin (China/EUA) Mathematical analysis and numerical methods for multiscale kinetic equations with uncertainties Resumo: Kinetic modeling and computation face the challenges of multiple scales and uncertainties. Developing efficient multiscale computational methods, and quantifying uncertainties arising in their collision kernels or scattering coefficients, initial or boundary data, forcing terms, geometry, etc. have important engineering and industrial applications. In this article we will report our recent progress in the study of multiscale kinetic equations with uncertainties modelled by random inputs. We first study the mathematical properties of uncertain kinetic equations, including their regularity and longtime behavior in the random space, and sensitivity of their solutions with respect to the input and scaling parameters. Using the hypocoercivity of kinetic operators, we provide a general framework to study these mathematical properties for general class of linear and nonlinear kinetic equations in various asymptotic regimes. We then approximate these equations in random space by the stochastic Galerkin methods, study the numerical accuracy and longtime behavior of the methods, and furthermore, make the methods “stochastically asymptotic preserving”, in order to handle the multiple scales efficiently. 
10.5  17.5  Maria Esteban (França) Symmetry and symmetry breaking: Rigidity and flows in elliptic PDEs Resumo: The issue of symmetry and symmetry breaking is fundamental in all areas of science. Symmetry is often assimilated to order and beauty while symmetry breaking is the source of many interesting phenomena such as phase transitions, instabilities, segregation, selforganization, etc. In this contribution we review a series of sharp results of symmetry of nonnegative solutions of nonlinear elliptic differential equation associated with minimization problems on Euclidean spaces or manifolds. Nonnegative solutions of those equations are unique, a property that can also be interpreted as a rigidity result. The method relies on linear and nonlinear flows which reveal deep and robust properties of a large class of variational problems. Local results on linear instability leading to symmetry breaking and the bifurcation of nonsymmetric branches of solutions are reinterpreted in a larger, global, variational picture in which our flows characterize directions of descent. 
12.6  17.6  Josselin Garnier (França) Multiscale analysis of wave propagation in random media Resumo: Wave propagation in random media can be studied by multiscale and stochastic analysis. We review some recent advances and their applications. In particular, in a physically relevant regime of separation of scales, wave propagation is governed by a Schrödingertype equation driven by a Brownian field. We study the associated moment equations and describe the propagation of coherent and incoherent waves. We quantify the scintillation of the wave and the fluctuations of the Wigner distribution. These results make it possible to introduce and characterize correlationbased imaging methods. 
12.7  17.7  Sem Borst (Holanda) Scalable load balancing in networked systems: Universality properties and stochastic coupling methods Resumo: We present an overview of scalable load balancing algorithms which provide favorable delay performance in largescale systems, and yet only require minimal implementation overhead. Aimed at a broad audience, the paper starts with an introduction to the basic load balancing scenario – referred to as the supermarket model – consisting of a single dispatcher where tasks arrive that must immediately be forwarded to one of $N$ singleserver queues. The supermarket model is a dynamic counterpart of the classical ballsandbins setup where balls must be sequentially distributed across bins. A popular class of load balancing algorithms are powerof$d$ or JSQ($d$) policies, where an incoming task is assigned to a server with the shortest queue among $d$ servers selected uniformly at random. As the name reflects, this class includes the celebrated JointheShortestQueue (JSQ) policy as a special case ($d = N$), which has strong stochastic optimality properties and yields a mean waiting time that vanishes as $N$ grows large for any fixed subcritical load. However, a nominal implementation of the JSQ policy involves a prohibitive communication burden in largescale deployments. In contrast, a simple random assignment policy ($d = 1$) does not entail any communication overhead, but the mean waiting time remains constant as $N$ grows large for any fixed positive load. In order to examine the fundamental tradeoff between delay performance and implementation overhead, we consider an asymptotic regime where the diversity parameter $d(N)$ depends on $N$. We investigate what growth rate of $d(N)$ is required to match the optimal performance of the JSQ policy on fluid and diffusion scale, and achieve a vanishing waiting time in the limit. The results demonstrate that the asymptotics for the JSQ($d(N)$) policy are insensitive to the exact growth rate of $d(N)$, as long as the latter is sufficiently fast, implying that the optimality of the JSQ policy can asymptotically be preserved while dramatically reducing the communication overhead. Stochastic coupling techniques play an instrumental role in establishing the asymptotic optimality and universality properties, and augmentations of the coupling constructions allow these properties to be extended to infiniteserver settings and network scenarios. We additionally show how the communication overhead can be reduced yet further by the socalled JointheIdleQueue (JIQ) scheme, leveraging memory at the dispatcher to keep track of idle servers. 
17.8  Amit Singer (EUA) Mathematics for cryoelectron microscopy Resumo: Singleparticle cryoelectron microscopy (cryoEM) has recently joined Xray crystallography and NMR spectroscopy as a highresolution structural method for biological macromolecules. CryoEM was selected by Nature Methods as Method of the Year 2015, large scale investments in cryoEM facilities are being made all over the world, and the Nobel Prize in Chemistry 2017 was awarded to Jacques Dubochet, Joachim Frank and Richard Henderson “for developing cryoelectron microscopy for the highresolution structure determination of biomolecules in solution”. This paper focuses on the mathematical principles underlying existing algorithms for structure determination using single particle cryoEM.  
10.8  17.9  PierreEmmanuel Jabin (França) Quantitative estimates for Advective Equation with degenerate anelastic constraint Resumo: In these proceedings we are interested in quantitative estimates for advective equations with an anelastic constraint in presence of vacuum. More precisely, we derive a quantitative stability estimate and obtain the existence of renormalized solutions. Our main objective is to show the flexibility of the method introduced recently by the authors for the compressible Navier–Stokes' system. This method seems to be well adapted in general to provide regularity estimates on the density of compressible transport equations with possible vacuum state and low regularity of the transport velocity field; the advective equation with degenerate anelastic constraint considered here is another good example of that. As a final application we obtain the existence of global renormalized solution to the socalled lake equation with possibly vanishing topography. 
17.10  Andrea Bertozzi (EUA) A review on high order wellbalanced pathconservative finite volume schemes for geophysical flows Resumo: In this work a general strategy to design high order wellbalanced schemes for hyperbolic system with nonconservative products and/or source terms is reviewed. We briefly recall the theory of Dal Maso–LeFloch–Murat to define weak solutions of nonconservative systems and how it has been used to establish the notion of pathconservative schemes. Next, a family of high order finite volume methods combining a reconstruction operator and a first order pathconservative scheme is described. Then, the wellbalanced property of the proposed methods is analyzed. Finally, some challenging examples on tsunami modeling are shown.  
17.11  Pierre Degond (Reino Unido) Mathematical models of collective dynamics and selforganization Resumo: In this paper, we beginning by reviewing a certain number of mathematical challenges posed by the modelling of collective dynamics and selforganization. Then, we focus on two specific problems, first, the derivation of fluid equations from particle dynamics of collective motion and second, the study of phase transitions and the stability of the associated equilibria.  
17.12  Richard James (EUA) Symmetry, invariance and the structure of matter Resumo: We present a mathematical view of the structure of matter based on the invariance of the classical equations of physics.  
17.13  Selim Esedoğlu (EUA) Algorithms for motion of networks by weighted mean curvature Resumo: I will report on recent developments in a class of algorithms, known as threshold dynamics, for computing the motion of interfaces by mean curvature. These algorithms try to generate the desired interfacial motion just by alternating two very simple operations: Convolution, and thresholding. They can be extended to the multiphase setting of networks of surfaces, and to motion by weighted (anisotropic) mean curvature, while maintaining the simplicity of the original version. These extensions are relevant in applications such as materials science, where they allow large scale simulation of models for microstructure evolution in polycrystals. 
18.1  Luis Radford (Canadá) On theories in mathematics education and their conceptual differences Resumo: In this article I discuss some theories in mathematics education research. My goal is to highlight some of their differences. How will I proceed? I could proceed by giving a definition, T, of the term theory and by choosing some differentiating criteria such as c1, c2, etc. Theories, then, could be distinguished in terms of whether or not they include the criteria c1, c2, etc. However, in this article I will take a different path. In the first part I will focus on a few wellknown theories in Mathematics Education and discuss their differences in terms of their theoretical stances. In the last part of the article, I will comment on a sociocultural emergent trend.  
18.2  Marianna Bosch Casabò (Espanha) Study and research paths: A model for inquiry Resumo: This paper presents a line of research in didactics of mathematics developed during the past decade within the Anthropological Theory of the Didactic around what we call study and research paths (SRPs). SRPs are initially proposed as a study format based on the inquiry of open questions, which can be implemented at all educational levels, from preschool to university, including teacher education and professional development. Additionally, they provide a general schema for analysing any kind of teaching and learning process, by especially pointing out the more or less explicit questions that lead the study process and the way new knowledge is built or introduced to elaborate answers to these questions. Current research on SRPs focuses on their didactic ecology, defined as the set of conditions required to generally implement SRPs at different educational levels, together with the constraints that hinder their development and dissemination.  
18.3  To be Confirmed (N/A) N/A Resumo: N/A  
18.4  Tadashi Tokieda (EUA), Simon Pampena (Austrália), Nikolai Andreev (Rússia), Kowei Lih (Taiwan), Rogério Martins (Portugal) e Mariana Pereira (Uruguai) Panel: New avenues for raising public awareness of mathematics. Resumo: N/A  
18.5  Sylvie Benzoni (França), Sujatha Ramdorai (Canadá), Robert Firmhofer (Polônia), Cindy Lawrence (EUA), Albrecht Beutelspacher (Alemanha) e Deborah Raphael (Brasil) Panel: Math museums: a worldwide explosion. Resumo: N/A  
18.6  Maitree Inprasitha (Tailândia), Stéphane Clivaz (Suíça), Mercy Kazima (Malawi), Akihiko Takahashi (EUA) e Rongjin Huang (EUA) Panel: Use of Lesson Study to support quality mathematics teaching. Resumo: N/A 
19.1  David Rowe (Alemanha) On Franco–German relations in mathematics, 1870–1920 Resumo: The first ICMs took place during a era when the longstanding rivalry between France and Germany strongly influenced European affairs. Relations between leading mathematicians of these two countries were also colored by this tense political atmosphere. This brief account highlights what was at stake by focusing on events in Paris and Göttingen from the period 1870 to 1920.  
19.2  Jan von Plato (Finlândia) In search of the sources of incompleteness Resumo: Kurt Gödel said of the discovery of his famous incompleteness theorem that he substituted “unprovable” for “false” in the paradoxical statement This sentence is false. Thereby he obtained something that states its own unprovability, so that if the statement is true, it should indeed be unprovable. The big methodical obstacle that Gödel solved so brilliantly was to code such a selfreferential statement in terms of arithmetic. The shorthand notes on incompleteness that Gödel had meticulously kept are examined for the first time, with a picture of the emergence of incompleteness different from the one the received story of its discovery suggests.  
19.3  Tatiana Roque (Brasil) IMPA's coming of age in a context of international reconfiguration of mathematics Resumo: In the middle of the $20^{th}$ century, the intimate link between science, industry and the state was stimulated, in its technicalscientific dimension, by the Cold War. Questions of a similar strategic nature were involved in the Brazilian political scene, when the CNPq was created. This presentation investigates the nature of the connection between this scientific policy and the presumed need for an advanced research institute in mathematics, that gave birth to IMPA. By retracing the scientific choices of the few mathematicians working at the institute in its first twenty years, we demonstrate how they paralleled the ongoing reconfiguration of scientific research. The development of dynamical systems theory provides a telling example of internationalization strategies which situated IMPA within a research network full of resources, that furnished, moreover, a modernizing drive adapted to the air of that time. 
O Comitê Organizador reservase ao direito de fazer modificações na Programação

Atualizado em 26 de junho de 2018