var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-11"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-9"><img src="//www2.math.ethz.ch/smsjs/images/arrow_right.png"/></a></div>    <div class="sms_title">      <span style="float: left;">SMS</span>      <span>SWISS MATHEMATICAL SOCIETY</span>      <span style="float: right;">SMG</span>    </div>    <div class="sms_info">      <span style="float: left; width: 250px;">Bulletin no. 5</span>      <span style="float: right; text-align:right; width: 250px;">13.10 - 17.10.2025</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Autumn Semester 2025</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, October 13      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPFL Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/labs/hessbellwald-lab/seminar/epfl-topology-seminar-fall-2024/">Séminaire de Topologie </a></div><br /><div class="event_speaker"> Sungyeon Hong (Australian National University)</div><div class="event_title">Complexity? Topology? Well, Cybernetics! <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk, I will walk you through my core interests in research, a blend of complexity science and topological data analysis – well, cybernetics in sum! After telling you a little bit of background story, I will spend some time presenting a paper recently delivered at a conference as a joint work with Ben Swift, entitled “Semantic Topologies in the Recursive Application of GenAI Models”, for a wider discussion.</div><div class="event_time">11:00 &bull; EPFL Lausanne, Mathematics</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/fim/activities/nachdiplom-lectures">Nachdiplomvorlesung</a></div><br /><div class="event_speaker"> Eugenia Malinnikova (Stanford University)</div><div class="event_title">Carleman estimates, unique continuation, and Landis conjecture</div><div class="event_time">13:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/talks-in-mathematical-physics">Talks in Mathematical Physics</a></div><br /><div class="event_speaker"> Tsviqa Lakrec (University of Geneva)</div><div class="event_title">Tilings and Cluster Algebras for the Amplituhedron <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />n 2005, Britto, Cachazo, Feng and Witten (BCFW) gave a recurrence relation for computing scattering amplitudes in N = 4 super Yang–Mills theory.In 2013, Golden, Goncharov, Spradlin, Vergu and Volovich discovered in the scattering amplitudes of this theory a cluster algebraic structure.The amplituhedron A(n,k,m) is a geometric object, introduced by Arkani-Hamed and Trnka in 2013, conjectured to encode scattering amplitudes in planar   N = 4 super Yang–Mills. In this talk, I will discuss the amplituhedron and how both the aforementioned BCFW recursion and cluster algebra structures are manifested in it.Based on joint works with Even-Zohar, Parisi, Sherman-Bennett, Tessler and Williams.</div><div class="event_time">13:30 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 25</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/symplectic-geometry-seminar">Symplectic Geometry Seminar</a></div><br /><div class="event_speaker"> Ángel  González-Prieto (Universidad Complutense de Madrid)</div><div class="event_title">Computability in dynamical systems <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The relationship between computational models and dynamical systems has fascinated mathematicians and computer scientists since the earliest formulations of computation. In recent years, this connection has attracted renewed interest, driven by groundbreaking results showing that Turing machines can be simulated by the flow lines of solutions to the Euler and Navier–Stokes equations.In this talk, we propose a novel viewpoint on computability within dynamical systems, inspired by ideas from Topological Quantum Field Theory. We prove that any computable function can be realized as the flow of a volume-preserving vector field on a smooth bordism. Beyond providing a new computational model, this perspective reveals deep connections between the topological features of the flow, the existence of compatible contact-type geometric structures on the bordism, and the computational complexity of the function.Joint work with E. Miranda and D. Peralta-Salas</div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_be"><a class="external" href="https://www.unibe.ch">Universität Bern</a></div><div class="event_type"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Mathematisches Kolloquium </a></div><br /><div class="event_speaker">Prof. Dr. Martin J. Gander (University of Geneva)</div><div class="event_title"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Landmarks in the History of Iterative Methods for Linear Systems</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Iterative methods for linear systems were invented for the same reasons as they are used today, namely to reduce computational cost. Gauss states in a letter to his friend Gerling in 1823: "you will in the future hardly eliminate directly, at least not when you have more than two unknowns".After a historical introduction to such classical stationary iterative methods, I will explain how the idea of extrapolation leads to Krylov methods, which are in fact not solvers but convergence accelerators.I will then introduce modern iterative methods for solving partial differential equations, which come in two main classes: domain decomposition methods and multigrid methods. These methods develop their full potential when used together with Krylov methods, namely as preconditioners.Reference:Landmarks in the History of Iterative Methods, Martin J. Gander,Philippe Henry and Gerhard Wanner, SIAM Review, 2025</div><div class="event_time">17:15 &bull; Universität Bern, Sidlerstrasse 5, 3012 Bern, Room B6</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, October 14      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/annonces/groupes-geometrie">Groupes et Géométrie </a></div><br /><div class="event_speaker"> Victor Jaeck (ETH Zürich)</div><div class="event_title">The Real Spectrum Compactification of Character Varieties and its Relationship with Other Compactifications <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We study the moduli space of marked hyperbolic surfaces and related objects. Thurston shows that this space can be identified with the space of faithful and discrete representations of a finitely generated group in PSL(2,R), up to post-conjugation by PSL(2,R). This space is a key connected component of the character variety.In this seminar, we examine degenerations of these representations by studying compactifications of the character variety. In particular, we present the real spectrum compactification, its topological properties, and show that it projects continuously onto the oriented Gromov equivariant compactification of the character variety, defined by Maxime Wolff. To this end, we interpret its boundary points geometrically and associate group actions on oriented real trees with them.</div><div class="event_time">10:30 &bull; Université de Genève, Conseil Général 7-9, Room 1-05</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/algebraische-geometrie/">Seminar Algebra and Geometry</a></div><br /><div class="event_speaker"> Antoine Pinardin (Universität Basel)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-algebra-and-geometry-antoine-pinardin-universitaet-basel/">Equivariant birational geometry of rational surfaces</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We will recall how the classification of the subgroups of Cremona up to conjugation relies on the study of groups of symmetries of rational varieties and equivariant birational equivalence. Two questions currently have a particular interest for researchers. A subgroup G of Cremona is linearizableif it is conjugated to a group of Automorphisms of the projective space. It is solid if, after regularization and G-MMP, it can only act on a Fano variety with invariant class group of rank one. We will give the complete answer to both questions in dimension 2. The answer for linearizability is a joint work with A.Sarikyan and E.Yasinsky.</div><div class="event_time">10:30 &bull; Universität Basel, Seminarraum 00.003, Spiegelgasse 1</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/fim/activities/nachdiplom-lectures">Nachdiplomvorlesung</a></div><br /><div class="event_speaker"> Eva Miranda (Universitat Politècnica de Catalunya)</div><div class="event_title">Singular Symplectic Manifolds</div><div class="event_time">13:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/annonces/seminaire-danalyse-numerique">Séminaire d\'Analyse Numérique </a></div><br /><div class="event_speaker"> Thomas Gauchery (Centre Inria de Saclay, Paris)</div><div class="event_title">Domain decomposition method for Navier-Stokes adjoint equations on anisotropic mesh <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This presentation focuses on a methodology for solving the adjoint Navier–Stokes equations in the framework of metric-based anisotropic mesh adaptation, where scalability and robustness are critical requirements. We propose a domain decomposition approach enhanced with a subdomain coloring algorithm, coupled with Symmetric Gauss–Seidel iterations employed as a local smoother within a preconditioned GMRES solver. Particular attention will be given to the scalability of the method on large-scale meshes and to its convergence behavior.</div><div class="event_time">14:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-05</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_dis"><a class="external" href="https://unidistance.ch">UniDistance Suisse</a></div><div class="event_type"><a class="external" href="https://unidistance.ch/en/mathematiques-et-informatique/recherche/number-theory/number-theory-seminar">Number Theory Seminar</a></div><br /><div class="event_speaker"> Cecilia  Busuioc  (University College London)</div><div class="event_title">A Modular Symbol with Values in Beilinson-Kato Distributions <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk, we will describe the construction of a GL_n(\\Q) -invariant modular symbol with coefficients in a space of distributions that take values in Milnor K-groups of  modular function fields. This is based on joint work with J. Park, O. Patashnick and G. Stevens.</div><div class="event_time">15:00 &bull; <a class="external" href="fernuni.zoom.us/my/davidloeffler">UniDistance Suisse</a></div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/analysis-seminar">Analysis Seminar</a></div><br /><div class="event_speaker">Dr. Gonzalo Cao-Labora  (EPFL)</div><div class="event_title">Unstable singularities in fluids via neural networks and computer-assisted proofs <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We will start talking about how to use neural networks to find unstable self-similar profiles in fluids PDE. These profiles are numerical, but are accurate up to machine precisionWe will then spend most of our time explaining how to use computer-assisted proofs (CAP) to rigorously prove singularity formation around those unstable solutions. The main ingredients are CAP operator norm bounds to reduce the linear problem to a finite-dimensional one, and CAP bounds on the linear propagator applied to the remaining finitely many modes.Lastly, we will briefly talk about recent work constructing the first counterexample of the Schiffer problem on the half-sphere, which is also the first contractible counterexample in any geometryJoint works with Google Deepmind, Yongji Wang, Ching-Yao Lai, Javier Gómez-Serrano, Tristan Buckmaster and Antonio J. Fernández</div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/zurich-colloquium-in-mathematics">Zurich Colloquium in Mathematics</a></div><br /><div class="event_speaker"> Hong Wang (IHES and NYU Courant)</div><div class="event_title">Kakeya sets in R^3 <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A Kakeya set is a compact subset of R^n that contains a unit line segment pointing in every direction.  Kakeya set conjecture asserts that every Kakeya set has Minkowski and  Hausdorff dimension n. We prove this conjecture in R^3 as a consequence of a more general statement about union of tubes.  This is joint work with Josh Zahl. </div><div class="event_time">16:30 &bull; ETH Zentrum, Building KO2, Room F 150</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, October 15      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde">Bernoullis Tafelrunde</a></div><br /><div class="event_speaker"> Charlotte Bartnick (Freiburg)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde/detail/bernoullis-tafelrunde-charlotte-bartnick-freiburg/">Differentially closed fields</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Differentially closed fields are the differential equivalent to algebraically closed fields. They provide a setting for model theorists to study differential algebraic questions. In this talk, we will introduce the theory DCF of differentially closed fields. We will focus on the more complex case of positive characteristic and explain some model theoretic properties of DCF. pdf version</div><div class="event_time">12:15 &bull; Universität Basel, Seminarraum 05.001, Spiegelgasse 5</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.math.uzh.ch/mat760">Ergodic theory and dynamical systems seminar</a></div><br /><div class="event_speaker">Prof. Dr. Pablo Shmerkin (University of British Columbia)</div><div class="event_title">Dynamical self-similarity in R^d <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>In 2019, I introduced the concept of self-similarity as a tool towards the proof of Furstenberg&apos;s slicing conjecture. I will discuss an extension of the theory to higher dimensions, obtained in joint work with E. Corso, and the higher-rank Furstenberg slicing estimate that follows.&lt;/p></div><div class="event_time">13:30 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 28</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/geometry-seminar">Geometry Seminar</a></div><br /><div class="event_speaker"> Jérémy Blanc (Université de Neuchâtel)</div><div class="event_title">Topological simplicity of the group of automorphisms of the affine plane <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The group AUT(A^n) of polynomial automorphisms of the space is not a simple group, as it contains the closed subgroup SAUT(A^n) of Jacobian 1. The group SAUT(A^2) is known to be abstractly not simple by a result of Danilov of 1974. The group SAUT(A^n) was however claimed to be topologically simple (no non-trivial closed normal subgroups) by Shafarevich in 1981. We will here prove this claim in dimension n=2 and give some ideas about the situation in higher dimension. This is over an infinite field, the case of finite fields being dramatically different.</div><div class="event_time">15:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/labs/stoan/probability-stochastic-analysis-seminar/">Probability (and Stochastic Analysis) Seminar </a></div><br /><div class="event_speaker"> Jonas Toelle (Aalto University)</div><div class="event_title">Ergodicity and mixing for locally monotone stochastic evolution equations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We establish general quantitative conditions for stochastic evolution equations with locally monotone drift and degenerate additive Wiener noise in variational formulation resulting in the existence of a unique invariant probability measure for the associated ergodic Markovian Feller semigroup. We prove improved moment estimates for the solutions and the $e$-property of the semigroup.Furthermore, we provide quantitative upper bounds for the Markovian $\\varepsilon$-mixing times.Examples include the stochastic incompressible 2D Navier-Stokes equations, shear thickening stochastic power-law fluid equations, the stochastic heat equation, as well as, stochastic semilinear equations such as the 1D stochastic Burgers equation. Joint work with Gerardo Barrera (IST Lisbon).</div><div class="event_time">16:00 &bull; EPF Lausanne, Bernoulli Center</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/sam/news-and-events/zhacm-colloquia">Zurich Colloquium in Applied and Computational Mathematics</a></div><br /><div class="event_speaker">Dr. Davide Pradovera (Stockholm University)</div><div class="event_title">Chasing resonances with adaptive rational approximation <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Frequency-domain models of wave propagation and vibration phenomena often give rise to large-scale linear systems and (potentially nonlinear) eigenvalue problems, whose solution is essential for tasks such as resonance analysis, design optimization, or uncertainty quantification. High-fidelity simulations, however, are typically too costly to be used directly in such applications. Model reduction and surrogate modeling thus play a central role.In this talk, we focus on rational approximation techniques that able to adaptively target the spectral features of interest. Building on ideas from reduced basis methods, we describe the "minimal rational interpolation" strategy, which adaptively selects frequency samples to construct accurate surrogates without oversampling. This allows us to approximate resonances efficiently and reliably.We further discuss how the same perspective can be leveraged to address parametric eigenvalue problems, where additional parameters are introduced to model, e.g., material or geometry variations or uncertainties. In such problems, eigenvalue manifolds may exhibit crossings, bifurcations, or even discontinuities as parameters vary. Our approach combines adaptive rational approximation with contour-integration-based eigensolvers to synthesize these manifolds in a robust way.This talk will cover joint work with Alessandro Borghi (TU Berlin), Ralf Hiptmair (ETH Zurich), and Ilaria Perugia (U Vienna).</div><div class="event_time">16:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.2</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.pauli-lectures.ethz.ch/">Wolfgang Pauli Lectures</a></div><br /><div class="event_speaker"> Hugo Duminil-Copin (University of Geneva)</div><div class="event_title">Can we truly understand by counting? <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />With an example borrowed from the research of Professor Hugo Duminil-Copin, we will illustrate how counting can shed light on the behavior of complex physical systems, while simultaneously revealing the need to sometimes go beyond what numbers tell us in order to unveil all the mysteries of the world around us.</div><div class="event_time">17:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room F 30</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Thursday, October 16      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/fim/activities/nachdiplom-lectures">Nachdiplomvorlesung</a></div><br /><div class="event_speaker"> Bo\'az Klartag (The Weizmann Institute of Science)</div><div class="event_title">Isoperimetric inequalities in high-dimensional convex sets</div><div class="event_time">10:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://theory.epfl.ch/seminar/">Theory and Combinatorics Seminar</a></div><br /><div class="event_speaker"> Anthony Ostuni</div><div class="event_title">Quasipolynomial Bounds for the Corners Theorem <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let G be a finite abelian group and A be a subset of G x G which is corner--free, meaning that there are no x, y in G and d in G \\ {0} such that (x, y), (x+d, y), (x, y+d) are in A. We prove that |A| &lt;= |G|^2  exp(-(log |G|)^{Omega(1)}).As a consequence, we obtain polynomial (in the input length) lower bounds on the nondeterministic communication complexity of Exactly-N in the 3-player Number-on-Forehead model. We also obtain the first “reasonable” lower bounds on the coloring version of the 3-dimensional corners problem, as well as on the nondeterministic communication complexity of Exactly-N in the 4-player Number-on-Forehead model.This talk is based on joint work with Michael Jaber, Yang P. Liu, Shachar Lovett, and Mehtaab Sawhney.</div><div class="event_time">11:00 &bull; EPF Lausanne, BC 329</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/zahlentheorie/">Seminar Zahlentheorie</a></div><br /><div class="event_speaker"> Remke Kloosterman (University of Padova)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/number-theory-seminar-remke-kloosterman-university-of-padova/">Title T.B.A.</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The average Mordell--Weil rank of elliptic surfaces over number fields Abstract: Let $K$ be a number field and let $n$ be a non-negative integer. In this talk we determine the average (arithmetic) Mordell--Weil rank of elliptic surfaces over $K$ with base curve $\\mathbb{P}^1$ and geometric genus $n$. Hereby we prove a conjecture of Alex Cowan, which in turn was inspired by Nagao\'s conjecture and subsequent work. The proof consists of two parts, the first part relies on work by Andr\\\'e and Maulik--Poonen on the jump loci of the Picard Number in flat families. This is sufficient to prove that the average Mordell--Weil rank equals the generic Mordell--Weil rank. The second part of the proof uses an argument involving quadratic twists in order to show that the generic Mordell--Weil rank of elliptic surfaces over a number field with fixed topological equals zero. Spiegelgasse 5, Seminarraum 05.001</div><div class="event_time">14:15 &bull; Universität Basel</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://stat.ethz.ch/events/research_seminar">Research Seminar in Statistics</a></div><br /><div class="event_speaker"> Marco Avelia Medina (Columbia University)</div><div class="event_title">A theoretical framework for M-posteriors: frequentist guarantees and robustness properties <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We provide a theoretical framework for a wide class of generalized posteriors that can be viewed as the natural Bayesian posterior counterpart of the class of M-estimators in the frequentist world. We call the members of this class M-posteriors and show that they are asymptotically normally distributed under mild conditions on the M-estimation loss and the prior. In particular, an M-posterior contracts in probability around a normal distribution centered at an M-estimator, showing frequentist consistency and suggesting some degree of robustness depending on the reference M-estimator. We formalize the robustness properties of the M-posteriors by a new characterization of the posterior influence function and a novel definition of breakdown point adapted for posterior distributions. We illustrate the wide applicability of our theory in various popular models and illustrate their empirical relevance in some numerical examples.This is joint work with Juraj Marusic and Cindy Rush</div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/schools/sb/research/math/statistics-seminars/">Statistics Seminar </a></div><br /><div class="event_speaker"> Matan Prasma</div><div class="event_title">Prospects for Higher Group Theory <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The characterisation of loop spaces as A-infinity spaces in the early 60\'s, suggested they constitute a homotopy-coherent analogue of groups. On the other hand, Higher Category Theory, allows us to identify loop spaces with pointed, connected 00-groupoids, or 00-groups. It is tempting to ask how much of ordinary group theory can be carried out to the homotopy-coherent framework, perhaps to constitute \'Higher Group Theory\'?  A decade ago, I tried to develop such a framework and obtained several partial results. In this talk, I\'ll present some of these results, like normal maps and their properties, isomorphism and Sylow theorems as well as prospects for future enquiries.   </div><div class="event_time">16:00 &bull; EPF Lausanne, CM 1 517</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPFL Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/labs/hessbellwald-lab/seminar/epfl-topology-seminar-fall-2024/">Séminaire de Topologie </a></div><br /><div class="event_speaker"> Matan Prazma</div><div class="event_title">Prospects for Higher Group Theory <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The characterisation of loop spaces as A-infinity spaces in the early 60\'s, suggested they constitute a homotopy-coherent analogue of groups. On the other hand, Higher Category Theory, allows us to identify loop spaces with pointed, connected 00-groupoids, or 00-groups. It is tempting to ask how much of ordinary group theory can be carried out to the homotopy-coherent framework, perhaps to constitute \'Higher Group Theory\'?  A decade ago, I tried to develop such a framework and obtained several partial results. In this talk, I\'ll present some of these results, like normal maps and their properties, isomorphism and Sylow theorems as well as prospects for future enquiries.  </div><div class="event_time">16:00 &bull; <a class="external" href="https://plan.epfl.ch/?room==CM%201%20517">EPFL Lausanne, Mathematics</a></div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/~palmeran/topsem.html">Séminaire de Topologie et Géométrie </a></div><br /><div class="event_speaker"> Ben-Michael Kohli (Université de Genève)</div><div class="event_title">Alexander-type properties of the Links-Gould invariant of links <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Links-Gould polynomial is a two-variable link invariant derived from the quantum supergroup \\(U_q(\\mathfrak{sl}(2|1))\\). It specializes to the classical Alexander polynomial, thereby generalizing it. Interestingly, several recent results have shown that the Links-Gould invariant shares some of the Alexander polynomial’s most geometric features—a surprising fact for a quantum invariant. In this talk, we will review these properties, then focus on proving that the Links-Gould polynomial and its colored counterparts provide lower bounds for the 3-genus of a knots that are quite precise. In particular, the 2-colored Links-Gould polynomial provides a genus bound that is sharp for all 1.7 million prime knots with up to 16 crossings.</div><div class="event_time">16:15 &bull; Université de Genève, Conseil Général 7-9, Room 1-15</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/talks-in-financial-and-insurance-mathematics">Talks in Financial and Insurance Mathematics</a></div><br /><div class="event_speaker">Dr. Florian Kogelbauer (ETH Zurich)</div><div class="event_title">Slow Spectral Manifolds in Kinetic Models <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We discuss recent developments around Hilbert\'s Sixth Problem about the passage from kinetic models to fluid equations. We employ the technique of slow spectral closure to rigorously establish the existence of hydrodynamic manifolds in the linear regime and derive new non-local fluid equations for rarefied flows independent of Knudsen number. We show the divergence of the Chapman--Enskog series for an explicit example and apply machine learning to learn the optimal hydrodynamic closure from DSMC data. The new dynamically optimal constitutive laws are applied to a rarefied flow problem. We then show how this geometric rational from dynamical systems theory can be applied analogously to the CEV model in finance and demonstrate how arbitrage opportunities can be related to bifurcations in market elasticity on the Fokker—Planck level.</div><div class="event_time">17:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.pauli-lectures.ethz.ch/">Wolfgang Pauli Lectures</a></div><br /><div class="event_speaker"> Hugo Duminil-Copin (University of Geneva)</div><div class="event_title">The mathematics of Phase transitions <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Phase transitions mark sudden, dramatic changes in the behavior of complex systems. To explore the mathematics behind these phenomena, we will focus on two of the most fundamental models in statistical physics: the Ising model and percolation. Originally introduced to capture ferromagnetism and the flow through porous media, these models have since evolved into a rich mathematical framework and a versatile tool for understanding abrupt shifts across diverse settings. In this talk, I will survey key advances in their study and highlight the broader insights they offer into the nature of phase transitions in statistical physics.</div><div class="event_time">17:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room F 30</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Friday, October 17      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_dis"><a class="external" href="https://unidistance.ch">UniDistance Suisse</a></div><div class="event_type"><a class="external" href="https://unidistance.ch/en/mathematiques-et-informatique/recherche/number-theory/number-theory-seminar">Number Theory Seminar</a></div><br /><div class="event_speaker">Prof. Dr. Pierre Colmez (CNRS)</div><div class="event_speaker">Dr. Andrew Graham (University of Oxford)</div><div class="event_speaker">Prof. Dr. Andreas Langer (University of Exeter)</div><div class="event_speaker">Prof. Dr. Wieslawa Niziol (CNRS)</div><div class="event_title"><a class="external" href="https://people.math.ethz.ch/~zerbess/ArithmeticaTransalpina.html">Arithmetica Transalpina</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This is the fifth meeting of the Arithmetica Transalpina, a joint Number Theory seminar between ETH Zürich, Unidistance Suisse, the Universities of Milan, Padova, Genova and Vienna.To register, please send an email to arithmeticatransalpina@gmail.comThe deadline for registration is September 30.</div><div class="event_time"> &bull; <a class="external" href="https://unidistance.ch/evenement/arithmetica-transalpina-2025">UniDistance Suisse, Schinerstrasse 18, 3900 Brigue</a></div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.pauli-lectures.ethz.ch/">Wolfgang Pauli Lectures</a></div><br /><div class="event_speaker"> Hugo Duminil-Copin (University of Geneva)</div><div class="event_title">Towards a rigorous Coulomb Gas Formalism <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk, we will explore the rich interplay between two-dimensional critical percolation models and the six-vertex model, a classical integrable random height model. By leveraging the remarkable symmetries and emergent structures that arise in the large-scale behavior of these systems, we will discuss how the so-called Coulomb Gas Formalism may be placed on rigorous mathematical foundations in this context. This perspective opens new pathways toward a deeper mathematical understanding of the phase transition of these models. The presentation is intended to be accessible to a broad mathematical audience.</div><div class="event_time">11:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room D 16.2</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/seminar-in-numerical-analysis">Seminar in Numerical Analysis</a></div><br /><div class="event_speaker"> Marcella Bonazzoli (Inria, Institut Polytechnique de Paris)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-in-numerical-analysis-marcella-bonazzoli-inria-institut-polytechnique-de-paris/">Seismic imaging of a dam-rock interface using Full Waveform Inversion</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk we are interested in reconstructing the interface between the concrete structure of a hydroelectric gravity dam and the underlying rock, using Full Waveform Inversion. Indeed, it appears that the roughness of the dam-rock interface has an effect on the sliding stability of gravity dams. We minimize a regularized misfit cost functional by computing its shape derivative and iteratively updating the interface shape by the gradient descent method. At each iteration, we simulate time-harmonic elasto-acoustic wave propagation models, coupling linear elasticity in the solid medium with acoustics in the reservoir. Numerical results using realistic noisy synthetic data demonstrate the method ability to accurately reconstruct the dam-rock interface, even with a limited number of measurements. This is joint work with Mohamed Aziz Boukraa, Lorenzo Audibert, Houssem Haddar and Denis Vautrin. For further information about the seminar, please visit this webpage .</div><div class="event_time">11:00 &bull; Universität Basel, Room 05.001, Spiegelgasse 5, 4051 Basel</div>        </div>        <div class="day_content_item important"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/analysis-seminar">Analysis Seminar</a></div><br /><div class="event_speaker">Prof. Dr. Michael Novack (Louisiana State University,)</div><div class="event_title">Special Analysis Seminar: Plateau\'s problem for soap films with positive volume: new directions <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We discuss a Plateau problem based on capillarity theory in which soap films are described as sets with small volume v that satisfy a spanning condition. Existence and interior regularity are understood for fixed v>0 and for the limiting Plateau problem, and so several questions arise regarding boundary regularity and the nature of the convergence to minimal surfaces as v approaches zero. We present ongoing joint work in these directions with Francesco Maggi (UT Austin) and Daniel Restrepo (Johns Hopkins). </div><div class="event_time">12:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/daco-seminar">DACO Seminar</a></div><br /><div class="event_speaker"> Ittai Rubinstein (MIT, US)</div><div class="event_title">Data Attribution in High-Dimensions and without Strong Convexity <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Data attribution methods aim to quantify how training examples shape model predictions, supporting applications in interpretability, unlearning, and robustness. The dominant tools in practice are influence functions (IF) and Newton step (NS) approximations, yet their theoretical guarantees and practical accuracy have remained poorly understood. In this talk, I will present new analytic techniques that uncover the scaling laws of the approximation error of IF and NS. Our results improve on prior analyses both by establishing asymptotically sharper bounds and by avoiding dependence on the global strong convexity parameter, which is often prohibitively small in practice. These insights not only explain long-standing empirical observations—such as why and when NS is more accurate than IF—but also guide the design of new methods. As an application, I will present rescaled influence functions (RIF), a simple, drop-in replacement for IF that matches the efficiency of IF while achieving the accuracy of NS. I will discuss both theoretical advances and empirical results on real-world datasets. Together, these contributions provide a first principled understanding of data attribution methods and demonstrate how to turn this understanding into more reliable tools.</div><div class="event_time">13:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 26.3</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/labs/anmath/seminars/">Seminar of Analysis </a></div><br /><div class="event_speaker"> Istvan Kadar (ETH Zürich)</div><div class="event_title">Smooth singularity formation for the energy critical wave equation without quantization I: Approximate solutions <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk, I present ongoing work on singularity formation for the energy-critical nonlinear wave equation (NW) in three dimensions. In their foundational work, Krieger-Schlag-Tataru constructed non-smooth solutions to (NW) that develop singularities with arbitrarily fast, polynomial blow-up rates exceeding the self-similar rate. For comparison, their analogous results for the wave map equation stand in sharp contrast to the quantized blow-up rates for smooth solutions obtained by Raphaël-Rodnianski. In this talk, I discuss a new result establishing the existence of smooth approximate solutions to (NW) that develop singularities at a continuum of polynomial rates, achieved through the collapse of multiple solitons.</div><div class="event_time">14:15 &bull; EPF Lausanne, MA B1 11</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Hyeonjun Park (Korea Institute for Advanced Study)</div><div class="event_title">Lagrangian classes and GLSM CohFT <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk, I will explain the construction of Lagrangian classes for perverse sheaves in cohomological Donaldson-Thomas theory, whose existence was conjectured by Joyce. The two key ingredients are a relative version of the DT perverse sheaves and a hyperbolic version of the dimensional reduction theorem. As a special case, we recover Borisov-Joyce/Oh-Thomas virtual classes in DT4 theory. As an application, I will explain how to construct cohomological field theories for gauged linear sigma models. This is joint work in progress with Adeel Khan, Tasuki Kinjo, and Pavel Safronov.</div><div class="event_time">16:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_be"><a class="external" href="https://www.unibe.ch">Universität Bern</a></div><div class="event_type"><a class="external" href="https://www.imsv.unibe.ch/research/talks/colloquia/index_eng.html">Colloquia on Probability and Statistics </a></div><br /><div class="event_speaker">Prof. Dr. Bastian Rieck (Universität Fribourg)</div><div class="event_title"><a class="external" href="https://www.imsv.unibe.ch/research/talks/schedule/index_eng.html">Shapes, Spaces, Simplices, and Structure: Geometry, Topology, and Machine Learning</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A large driver contributing to the undeniable success of deep-learning models is their ability to synthesize task-specific features from data. For a long time, the predominant belief was that \'given enough data, all features can be learned.\' However, as large language models are hitting diminishing returns in output quality while requiring an ever-increasing amount of training data and compute, new approaches are required. One promising avenue involves focusing more on aspects of modeling, which involves the development of novel inductive biases such as invariances that cannot be readily gleaned from the data.This approach is particularly useful for data sets that model real-world phenomena, as well as applications where data availability is scarce.Given their dual nature, geometry and topology provide a rich source of potential inductive biases. In this talk, I will present novel advances in harnessing multi-scale geometrical-topological characteristics of data. A special focus will be given to show how geometry and topology can improve representation learning tasks. Underscoring the generality of a hybrid geometrical-topological perspective, I will furthermore showcase applications from a diverse set of data domains, including point clouds, graphs, and higher-order combinatorial complexes.</div><div class="event_time">16:15 &bull; Universität Bern, Sidlerstrasse 5, 3012 Bern, Room B77</div>        </div>      </div>    </div>  </div>  <div id="sms_footer">    address: Alessandra Naldi Windler, Departement Mathematik, HG G 51.4, ETH Zurich, Raemistrasse 101, CH-8092 Zurich<br />    email: <a href="mailto:bulletin@math.ch">bulletin@math.ch</a> | phone: +41 44 632 3684 | url: <a href="https://math.ch">https://math.ch</a>    <br /><br /><img src="//www2.math.ethz.ch/smsjs/sms_logo.gif" width="150" alt="SMS/SMG Logo" title="SMS/SMG Logo" />  </div></div>';