var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-3"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-1"><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. 13</span>      <span style="float: right; text-align:right; width: 250px;">8.12 - 12.12.2025</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, December 8      </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"> 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://ethz.ch">ETH 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"> Eva Miranda (U. Politecnica de Catalunya)</div><div class="event_title">Quantizing Poisson Manifolds Through Their Symplectic Avatars <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This talk presents a new approach to the quantization of Poisson manifolds with linearizable transverse Poisson structure through what I call their symplectic avatars: E-symplectic manifolds naturally associated with a given Poisson structure. These avatars provide accessible symplectic models that preserve the core features of the underlying Poisson geometry while allowing the use of powerful symplectic techniques.I will begin with the case of b-symplectic manifolds, showing how their geometric and deformation quantization can be explicitly determined and vividly illustrated in the presence of additional symmetries using the language of Delzant polytopes. This example demonstrates how singular symplectic structures offer a fertile testing ground for quantization beyond the classical smooth setting.I will conclude the talk with a desingularization theorem for linearizable transverse Poisson structures (joint work with Ryszard Nest), establishing that they can be desingularized by suitable E-symplectic avatars. I will discuss how this desingularization principle opens new avenues for both geometric and deformation quantization, effectively bridging Poisson and symplectic worlds.</div><div class="event_time">13:30 &bull; ETH Zentrum, 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"> Skander Charfi (Laboratoire de Mathématiques d\'Orsay)</div><div class="event_title">A Multidimensional Birkhoff Theorem for Recurrent Lagrangian Submanifolds <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A classical theorem of Birkhoff (1922) asserts that any essential invariant curve of a symplectic twist map on the cylinder is a Lipschitz graph over the circle. Since then, several extensions of this result to higher-dimensional settings have been obtained (Herman, Katznelson–Ornstein, Siburg, Bialy–Polterovich, among others). A generalization due to Arnaud (2010) in the contangent bundle of any closed manifold, states that an invariant exact Lagrangian, under the flow of a convex Hamiltonian, is a C1 graph over the base. We will try to show that this graph property is not a consequence of invariance itself but rather of recurrence. We will provide an optimal condition on the orbit of an exact Lagrangian submanifold under the Hamiltonian flow, requiring backward and forward convergence (up to subsequences) in a topology controlling the Liouville primitives, which ensures that the submanifold and all its iterates are C1 graphs over the base. We will see that this implies recurrence. The proof combines two complementary viewpoints on weak solutions of the Hamilton–Jacobi equation : the variational viewpoint via graph selectors of exact Lagrangian submanifolds, and the regularity properties of viscosity solutions provided by the weak-KAM approach.</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_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/mpseminar/seminar.html">Séminaire de Mathématique Physique </a></div><br /><div class="event_speaker"> Claudio  Dappiaggi  (University of Pavia)</div><div class="event_title">Title T.B.A.</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_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">Dr. Patrick Bammer (University of Bern)</div><div class="event_title"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Adaptivity based on Local Error Reductions</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In the finite element method, the weak formulation of a partial differential equation is projected onto a finite-dimensional approximation space, which is based on decomposing the given domain into (physical) elements. An a priori error analysis indicates that the accuracy of the discrete solution of the projected problem can be improved either by subdividing elements or by increasing the approximation order on elements. If such modifications, particularly combinations of both, are applied only to selected elements, the process is known as adaptive refinement.         To steer adaptive refinements, typically, a posteriori error estimators are used, which identify those elements that contribute most to the overall approximation error and, hence, should be refined. In this talk, however, a new adaptive refinement procedure is introduced that predicts the expected reduction in the (global) energy error for various refinement options on each element.</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, December 9      </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"> Corentin  Bodart (Oxford)</div><div class="event_title">Subgroup membership and formal languages <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The intersection of Geometric Group Theory and Formal Language Theory has been fruitful in the last 50 years. I\'ll start by recalling some of the key results in the area, such as the Muller-Schupp theorem on groups with context-free Word Problem and Lehnert\'s conjecture on groups with co-context-free Word Problem. In joint work with André Carvalho and Carl-Fredrik Nyberg-Brodda, we have been looking at similar languages related to another decision problem in groups: Subgroup Membership. I\'ll explain the toolbox we have been developing, apply it to examples and non-examples, and highlight some open problems along the way.</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"> Claudia Stadlmayr (Neuchâtel)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-algebra-and-geometry-claudia-stadlmayr-neuchatel/">Infinitesimal symmetry in algebraic geometry: group schemes and del Pezzo surfaces</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Group schemes provide a refined notion of symmetry in positive characteristic: they detect infinitesimal structure invisible to the discrete automorphism group. Classical examples such as mu_p or alpha_p equip the trivial topological space with a non-trivial algebraic structure. In this talk I will explain how this perspective can be used to classify weak and RDP del Pezzo surfaces admitting global vector fields, and how phenomena unique to small characteristic - such as non-lifting vector fields on rational double point singularities (RDPs) - can be illuminated using the group-scheme framework. If time permits, I will outline applications and ongoing projects: towards higher-dimensional Fano varieties with infinite automorphism groups and (equivariant) compactifications of the affine plane.</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_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"> Guifré Sánchez i Serra (EPFL)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde/detail/guifre-sanchez-i-serra-epfl/">Alternating and parallel tensor-train methods: local convergence and preconditioning ideas for large eigenvalue problems</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Density Matrix Renormalization Group algorithm (DMRG) is a popular alternating optimization scheme to solve high-dimensional eigenvalue problems arising in the context of quantum many-body systems. In recent years, the development of several low-rank tensor formats has enabled the design and analysis of new methods capable of approximating, with high accuracy, the solutions of such large-scale problems. One format that has proven particularly successful in tackling tensor-structured linear and eigenvalue problems is the tensor-train format, introduced to the numerical analysis community, long after it had been known and used by the quantum physics community under the name of matrix product states. The equivalence between these two notions has allowed for a more rigorous treatment of the DMRG algorithm, which can now be understood as an alternating scheme for addressing general high-dimensional optimization problems. Although many convergence properties of DMRG remain poorly understood, some satisfactory results have been obtained regarding its local convergence behavior. Thus, in the first part of this talk, I will introduce the main tools involved in analyzing the local convergence properties of DMRG, and extend these tools to obtain an analogous result for a recent parallel version of the algorithm, inspired by two-level additive Schwarz methods. The search for a parallel version of DMRG is motivated by its inherently sequential nature, which generally hinders efficient implementation on parallel computing architectures and thus limits its overall computational cost. Related developments have recently demonstrated how to efficiently construct algebraic two-level additive Schwarz preconditioners that significantly accelerate iterative linear solvers such as CG. In the second part of this talk, I will give an overview of preconditioning strategies for (symmetric) eigenvalue problems, discuss their impact on the convergence behavior of iterative eigensolvers (e.g. Jacobi-Davidson, LOBPCG), and describe ongoing work aimed at adapting additive Schwarz ideas in this context. pdf_version</div><div class="event_time">12:15 &bull; Universität Basel, Seminarraum 05.001</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"> Nicola Guglielmi (GSSI, L\'Aquilla)</div><div class="event_title">Changing the ranking in eigenvector centrality of a weighted graph by small perturbations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We consider the problem of ranking nodes in a weighted graph based on eigenvector centrality. This measure assigns importance to each node according to the entries of the Perron eigenvector of the adjacency matrix. Our goal is to investigate how small perturbations of the edge weights affect this ranking, thereby revealing the robustness and sensitivity of the centrality measure. We formulate this as a matrix nearness problem, which is solved through an iterative algorithm. The approach provides quantitative insight into how fragile or stable a network’s hierarchy is under small structural changes.   This is based on joint projects with Michele Benzi (SNS, Pisa) and Christian Lubich (University of Tübingen). </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"> Enrico Da Ronche (University of Genova)</div><div class="event_title"> Kolyvagin\'s conjecture for non-ordinary modular forms <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Kolyvagin\'s conjecture predicts the existence of a non-trivialclass in the system built by Kolyvagin starting from Heegner points on elliptic curves. Thanks to Heegner cycles built by Besser on Kuga-Sato varieties over Shimura curves, it is possible to build a system of Kolyvagin classes attached to a modular form of any weight, whose non-triviality was proved by Longo, Pati and Vigni in the ordinary case.In this talk we will see how these classes are built and we will give a sketch of the proof of the conjecture in the non-ordinary setting.</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_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/seminaires/lie-sem/">Lie groups and moduli spaces </a></div><br /><div class="event_speaker"> Nikolai  Perry  (Université de Genève)</div><div class="event_title">Modified necklace Lie bialgebras & quartic BV structures in supercategories <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We introduce modified versions of the necklace Lie bialgebra associated to a quiver, in which the bracket and cobracket insert (rather than remove) pairs of arrows in involution. These structures are related to canonical quartic Poisson/Batalin-Vilkovisky structures on suitable representation varieties of the quiver. Constructions on the representation side will take place in any suitable symmetric monoidal category, the generality of which allows us to fully recover necklace structures, giving them a new conceptual origin and revealing how the modified and classical necklace operations are related via dualisability. A broader aim of this talk is to highlight the following: (1) naïve generalisations can be fruitful, and (2) notation should be taken seriously. Time permitting, we will conclude with a few open questions.Based on recent work arXiv:2509.07975 [math.QA].</div><div class="event_time">15:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ne"><a class="external" href="https://unine.ch">Université de Neuchâtel</a></div><div class="event_type"><a class="external" href="http://www.unine.ch/math/home/colloques_et_seminaires/les-colloques-du-mardi.html">Colloque du Mardi </a></div><br /><div class="event_speaker"> Tsviqa Lakrec (Université de Genève)</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 />Recent years have seen the discovery of many intriguing mathematical structures in particle physics scattering amplitudes. One such geometric structure is the amplituhedron (Arkani-Hamed--Trnka 2013), a generalization of the nonnegative Grassmannian with rich combinatorial and geometric structure. Its "volume\'\' expresses scattering amplitudes in certain quantum field theories. Another such phenomenon is the appearance of cluster-algebraic structures in scattering amplitudes (starting with Golden-Goncharov-Spradlin-Vergu-Volovich 2013). In this talk I will introduce these topics and discuss how they are connected and clarified using the recursion relations for scattering amplitudes introduced by Britto, Cachazo, Feng and Witten (BCFW 2005). Based on joint works with Even-Zohar, Parisi, Sherman-Bennett, Tessler and Williams.</div><div class="event_time">16:00 &bull; Université de Neuchâtel, Rue Emile-Argand 11, Room B217</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_nolink">Paul Bernays Lectures</a></div><br /><div class="event_speaker"> Irit Dinur (IAS Princeton)</div><div class="event_title">Expanders from local to global </div><div class="event_time">16:00 &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">        Wednesday, December 10      </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/seminaires/lie-sem/">Lie groups and moduli spaces </a></div><br /><div class="event_speaker"> Arkady  Berenstein  (University of Oregon)</div><div class="event_title">Generalized electrical Lie algebras <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />My talk is based on joint work with Azat Gainutdinov and Vassily Gorbounov, in which we generalize in several ways the electrical Lie algebras originally introduced by Lam and Pylyavskyy. To each semisimple or Kac-Moody Lie algebra g we associate a family of flat deformations of its nilpotent part parametrized by the points of the Cartan subalgebra of g. If g=sl_n, then the generic electrical Lie algebra is sp_{n-1}, which is simple if n is odd. Similar situation is with other classical lie algebras, for instance if g=sp_{2n}, then its generic electrical Lie algebra is sp_n\\oplus sp_{n-1}, which is never semisimple. If time permits, I will explain the "edge models" of electrical Lie algebras in semisimple and affine case, where the deformation parameters can be viewed as edge weights of the Dynkin diagram of g. </div><div class="event_time">13:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</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">Andrea Ulliana (Universität Zürich)</div><div class="event_title">Delocalization of Eigenfunctions for Discrete Schrödinger Operators on Graphs <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>Schr&ouml;dinger operators and their localization phenomena play a central role in spectral theory and its connection to dynamical systems. In this talk, I will focus on discrete Schr&ouml;dinger operators defined on large finite graphs and investigate their asymptotic behavior as the graph size tends to infinity. In joint work with A. Avila, we establish a general criterion showing that for any family of graphs without eigenvalues concentration, delocalization of eigenfunctions become asymptotically dense in the space of potentials. Along the way, I will emphasize the interplay with ergodic Schr&ouml;dinger operators, where the potential is generated by an underlying topological dynamical system.&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/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Olivier de Gaay Fortman (University of Utrecht)</div><div class="event_title">Matroids, the integral Hodge conjecture for abelian varieties, and optimal algebraic multiples of the minimal class <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will discuss joint work with Philip Engel and Stefan Schreieder, in which we prove that the cohomology class of any curve on a very general principally polarized abelian variety of dimension at least 4 is an even multiple of the minimal class, and that the same holds for the intermediate Jacobian of a very general cubic threefold. This disproves the integral Hodge conjecture for abelian varieties and shows that verygeneral cubic threefolds are not stably rational. I will also discuss our most recent result, which shows that on a very general principally polarized abelian 6-fold, the smallest multiple of the minimal curve class which can be represented by an algebraic cycle is exactly 6. </div><div class="event_time">13:30 &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_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"> Alina Ostafe (UNSW)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/number-theory-seminar-alina-ostafe-unsw/">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 />Title: Counting linear recurrence sequences with zeros and solvable S-unit equations Abstract: In this talk I will discuss recent joint work with Carl Pomerance and Igor Shparlinski where we obtain a tight upper bound on the number of integer linear recurrence sequences which attain a zero value. The argument is based on modular techniques combined with a classical idea of P. Erdos. Using similar ideas, we also show that only a rather small proportion of linear equations are solvable in elements of a fixed finitely generated subgroup of a multiplicative group of a number field. Alte Universität - Seminarraum -201</div><div class="event_time">14:15 &bull; Universität Basel</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/analysis/analysis-seminar">Analysis Seminar</a></div><br /><div class="event_speaker"> Jingeon An (Universität Basel)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-analysis-and-mathematical-physics-jingeon-an-universitaet-basel/">Minimal surfaces and Allen-Cahn equations</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Minimal surfaces and Allen-Cahn equations are central subjects in Geometric Partial Differential Equations and Geometric Measure Theory. We provide a brief overview of the research history, with a particular focus on Allen-Cahn equations. Subsequently, we introduce a promising alternative to the Allen-Cahn equation, known as the free boundary Allen-Cahn equation.</div><div class="event_time">14:15 &bull; Universität Basel, Spiegelgasse 5, Seminarraum 05.002</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"> Antoine Pinardin (Universität Basel)</div><div class="event_title">Finite simple subgroups of the real Cremona group of rank three <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Very little is known about the classification of finite subgroups of Cremona in dimension three. It is natural to start with the case of simple groups, and this step was achieved by Prokhorov in 2009 over the field of complex numbers. In the work I will present, we show that the only non-cyclic finite simple subgroups of the real Cremona group of rank three are A5 and A6. This is a joint project with I. Cheltsov and Y. Prokhorov.</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"> Chiara Ricciuti (Imperial)</div><div class="event_title">Stochastic Burgers Equation from Non-Product Stationary Measures via a Generalised Second-Order Boltzmann-Gibbs Principle <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 present a generalised second-order Boltzmann-Gibbs principle for conservative interacting particle systems on a lattice whose stationary measures are not of product type and not invariant under particle jumps. The result, which requires neither a spectral gap bound nor an equivalence of ensembles, extends the classical framework to settings with correlated invariant measures and is based on quantitative bounds for the correlation decay. As an application, we show that the equilibrium density fluctuations of the Katz-Lebowitz-Spohn model, for a suitable choice of parameters, converge under diffusive scaling to the stationary energy solution of the stochastic Burgers equation. Based on joint work with P. Gonçalves and G. M. Schütz.</div><div class="event_time">15:30 &bull; EPF Lausanne, CM 1 517</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">Prof. Dr. Daniel Kressner (EPFL Lausanne)</div><div class="event_title">Randomized linear algebra in scientific computing <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Randomized algorithms are becoming increasingly popular in matrix computations. In fact, randomization is on the verge of replacing existing deterministic techniques for several large-scale linear algebra tasks in scientific computing. The poster child of these developments, randomized SVD, is now one of the state-of-the-art approaches for performing low-rank approximation. In this talk, we will go beyond the randomized SVD and illustrate the great potential of randomization to not only speed up existing algorithms, but to also yield novel and often simple algorithms for solving notoriously difficult problems. Examples covered in this talk include reduced order modeling, acceleration of scientific simulations, joint diagonalization, and large null space computation. A common theme of these developments is that randomization helps to transform linear algebra results that only hold generically into robust and reliable numerical algorithms.</div><div class="event_time">15:45 &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_nolink">Paul Bernays Lectures</a></div><br /><div class="event_speaker"> Irit Dinur (IAS Princeton)</div><div class="event_title">High dimensional expansion and locally testable codes</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 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/seminar-on-stochastic-processes">Seminar on Stochastic Processes</a></div><br /><div class="event_speaker">Dr. Francesco Pedrotti (ETH Z&uuml;rich, Switzerland)</div><div class="event_title">Cutoff for the proximal sampler via transport inequalities <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The cutoff phenomenon is a sharp transition in the convergence of high-dimensional Markov chains to equilibrium: the total variation distance remains close to 1 for a long time and then rapidly decreases to almost 0 over a much shorter time window.It was initially discovered in the context of card shuffling by Diaconis and Shahshahani, and since then observed in a variety of different models. In spite of its ubiquity, it is still largely unexplained, and most proofs are model-specific.In this talk, we discuss a high-level approach to establishing cutoff based on transport inequalities, and we illustrate it on a popular algorithm known as the proximal sampler, when the target measure on R<sup>d</sup> is log-concave.Based on joint work with Justin Salez.</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>    </div>    <div class="day">      <div class="day_title">        Thursday, December 11      </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">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://calendar.google.com/calendar/embed?mode=AGENDA&height=600&wkst=2&bgcolor=%23FFFFFF&src=t36it03v52cus2detrvinlgk18%40group.calendar.google.com&color=%235F6B02&ctz=Europe%2FZurich">Groups, Arithmetic and Algebraic Geometry Seminar </a></div><br /><div class="event_speaker"> Enrico Lampetti</div><div class="event_title">Title T.B.A.</div><div class="event_time">10:15 &bull; EPF Lausanne</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"> 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_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"> Shaoshi Chen (Academy of Mathematics and Systems Science, Chinese Academy of Sciences)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/number-theory-seminar-shaoshi-chen-academy-of-mathematics-and-systems-science-chinese-academy-of-sciences/">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 />Arithmetic Dynamics around Linear Differential Equations Abstract: We will talk about two types of dynamical systems coming from linear differential equations. The first dynamical system is defined by the coefficient sequence of a linear differential equation. We present a Skolem-Mahler-Lech type theorem on this dynamical system. The second dynamical system is defined by iterated integration of solutions of a linear differential equation. We present some stability results on the order of linear differential equations satisfied by the iterated integrals of these solutions.</div><div class="event_time">14:15 &bull; Universität 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://stat.ethz.ch/events/research_seminar">Research Seminar in Statistics</a></div><br /><div class="event_speaker"> Xinwei Shen (University of Washington)</div><div class="event_title">Change of time and room: Distributional Causal Inference: from Estimation to Simulation <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Classical causal inference typically targets low-dimensional estimands such as the average treatment effect. A richer understanding, however, requires characterizing the full outcome distribution under different treatments. In addition, the ability to simulate counterfactual outcomes is essential for causal model selection and evaluation. Recent advances in distributional learning provide a principled foundation for these goals. In this talk, we build on engression—a distributional learning approach—to develop methods for estimating distributional causal effects and generating data from causal models. We first introduce a distributional method for instrumental variable settings with unobserved confounders, enabling estimation of full interventional distributions from which classical estimands arise as functionals. When additional covariates are observed but marginal causal effects remain the central interest, as is common in clinical trials, we propose a framework that parametrizes the joint observed distribution around the causal margin with no redundancy. This allows for both estimation and simulation under user-specified interventions.Joint work with Anastasiia Holovchak, Sorawit Saengkyongam, Nicolai Meinshausen, Linying Yang, and Robin Evans</div><div class="event_time">16:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room E 5</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_nolink">Paul Bernays Lectures</a></div><br /><div class="event_speaker"> Irit Dinur (IAS Princeton)</div><div class="event_title">PCP agreement tests and topological covers</div><div class="event_time">17:00 &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_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. Aleksandar Arandjelovic (ETH Zurich)</div><div class="event_title">Algorithmic strategies in continuous-time hedging and stochastic integration <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We develop a rigorous framework for continuous-time algorithmic trading strategies from the point of view of mathematical finance.To this end, we first establish a universal approximation theorem for neural networks on locally convex spaces with respect to Orlicz-type topologies.When the underlying sigma-algebra is generated by a possibly uncountable family of random variables, we prove that neural networks, through functional representations, can approximate functions in these Orlicz spaces arbitrarily well.We then represent algorithmic strategies as simple predictable processes to establish their approximation capabilities in spaces of stochastic (integral) processes.As applications, we prove that algorithmic strategies can approximate mean-variance optimal hedging strategies arbitrarily well, we establish a no free lunch with vanishing risk condition for algorithmic strategies, and we obtain a \'neural\' version of the Bichteler-Dellacherie theorem.This talk is based on joint work with Uwe Schmock (TU Wien).</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>    </div>    <div class="day">      <div class="day_title">        Friday, December 12      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_sg"><a class="external" href="https://www.unisg.ch">Universit&auml;t St. Gallen</a></div><div class="event_type"><a class="external" href="https://www.math.uzh.ch/aa/?events">Neuchatel - St.Gallen - Zurich Seminar in Coding Theory and Cryptography</a></div><br /><div class="event_speaker">Cornelia Ott (Institute of Communications Engineering, Ulm University)</div><div class="event_title">Bounds on Codes in the Sum-Rank Metric <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p class="MsoNormal">&lt;span lang="EN-US">The sum-rank metric, which generalizes both the Hamming and rank metric, first appeared in 2005 in the context of space-time codes and later in 2010 for multi-shot network coding. It has since become a key tool with significant theoretical and practical relevance.&lt;/span>&lt;/p> &lt;p class="MsoNormal">&lt;span lang="EN-US">We investigate three classical bounds on the cardinality of sum-rank metric codes: the Singleton, Gilbert--Varshamov, and sphere-packing bound. Although these bounds and their asymptotic forms for the case of bounded block sizes with a growing number of blocks are known, their evaluation relies on computing the size of sum-rank metric balls, a task that is super-polynomial using existing closed formulas.&lt;/span>&lt;/p> &lt;p class="MsoNormal">&lt;span lang="EN-US">To address this, we revisit the Gilbert--Varshamov and sphere-packing bounds for linear codes, connect them to a known polynomial-time algorithm for computing sum-rank sphere sizes, and thereby obtain efficient polynomial-time methods for evaluating these bounds.&lt;/span>&lt;/p> &lt;p class="MsoNormal">&lt;span lang="EN-US">Moreover, by incorporating upper and lower estimates on sum-rank metric ball sizes, we derive simplified variants that further reduce computational complexity. These simplified bounds also yield new asymptotic versions of the Gilbert--Varshamov and the sphere-packing bound that apply not only when the number of blocks grows but also when block sizes grow and thereby extending previously established asymptotic results.&lt;/span>&lt;/p></div><div class="event_time">10:30 &bull; Uni St. Gallen, 64-110</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"> Gilles Vilmart (University of Geneva)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-in-numerical-analysis-gilles-vilmart-university-of-geneva/">Second order explicit stabilized multirate method for stiff differential equations with error control</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Explicit stabilized methods are highly efficient time integrators for large and stiff systems of ODEs especially when applied to semi-discrete parabolic problems. However, when local spatial mesh refinement is introduced, their efficiency decreases, since the stiffness is driven by only the smallest mesh element. A natural approach is to split the system into fast stiff and slower mildly stiff components. In this context, [A. Abdulle, M.J. Grote, and G. Rosilho de Souza 2022] proposed the order one multirate explicit stabilized method (mRKC). We extend their approach to second order and introduce the new multirate ROCK2 method (mROCK2), which achieves high precision and allows a step-size strategy with error control. This talk is based on joint work with Mathieu Benninghoff (University of Geneva). 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 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/number-theory-seminar">Number Theory Seminar</a></div><br /><div class="event_speaker">Dr. Noam Kimmel (University of Bonn)</div><div class="event_title">Zeros of Poincaré series <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We explore the zeros of certain Poincaré series P(k,m) of weight k and index m for the full modular group. These are distinguished modular forms, which have played a key role in the analytic theory of modular forms. We study the zeros of P(k,m) when the weight k tends to infinity. The case where the index m is constant was considered by Rankin who showed that in this case almost all of the zeros lie on the unit arc |z|=1. In this talk we will explore the location of the zeros when the index m grows with the weight k, finding a range of different limit laws. Along the way, we also establish a version of Quantum Unique Ergodicity for some ranges.</div><div class="event_time">14:15 &bull; Location T.B.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/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker"> Daniel Holmes (IST Austria)</div><div class="event_title">Interactions between Gromov-Witten theory and GKM theory <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />GKM spaces are important examples in algebraic and symplectic geometry, including smooth toric varieties, homogeneous spaces, smooth Schubert varieties, and non-algebraic examples like the twisted flag manifold. I will quickly introduce the main concepts of GKM theory and explain how the GKM graph completely determines the Gromov-Witten invariants and hence quantum cohomology of its space. This opens up a two-way interaction between the two theories: while GKM theory provides computability, GW theory provides necessary conditions for the Hamiltonian GKM realization problem. I will sketch some first results in both directions and introduce our new software package "GKMtools", which supports explicit computations at this intersection. Joint work with Giosuè Muratore.</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">Dr. Vanessa Piccolo (EPFL)</div><div class="event_title"><a class="external" href="https://www.imsv.unibe.ch/research/talks/schedule/index_eng.html">Eigenvalue distribution of random feature matrices</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In recent years, machine learning has motivated the study of nonlinear random matrices, that is, random matrices that involve the entrywise application of some deterministic nonlinear function. In this talk, we focus on matrices of the form YY* with Y = f(WX). Here, W and X are random rectangular matrices with i.i.d. centered entries, representing the weights and data in a two-layer feed-forward neural networks, and f is a nonlinear activation function. This setting is commonly known as the conjugate kernel or random feature model.When both W and X have light-tailed entries, the asymptotic behavior of the eigenvalues of YY* is by now well understood and coincides with that of a simple Gaussian-equivalent model. In recent joint work with Alice Guionnet, we investigate the case where W has heavy-tailed entries while X remains light-tailed. This regime is motivated by empirical observations on trained neural networks, whose learned weights often display strong correlations, and heavy-tailed distributions provide a realistic framework for modeling these correlations. In this setting, the matrix Y = f(WX) presents significantly stronger correlations than in the light-tailed case, leading to a completely new spectral behavior.&#8232;In this talk, I will discuss the classical global law results for random feature matrices in the light-tailed setting and present our recent results in the heavy-tailed regime.</div><div class="event_time">16:15 &bull; Universität Bern, IMSV, Alpeneggstrasse 22, 3012 Bern, Hörraum -203</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>';