var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-64"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-62"><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. 12</span>      <span style="float: right; text-align:right; width: 250px;">8.5 - 12.5.2023</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Spring Semester 2023</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, May 8      </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"> Carl Johansson (EPF Lausamme)</div><div class="event_title">Wild solutions to Euler-Lagrange equations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We study very weak solutions to Euler-Lagrange equations associated with qua- dratic convex functionals. After having introduced Sobolev spaces and some of their properties, we investigate whether the regularity of distributional W1,1 solutions can be improved. We answer positively in a suitable class of functionals. Conversely, using convex integration, we also provide counterexamples outside this class of functionals.</div><div class="event_time">12:15 &bull; Universität Basel, Spiegelgasse 5, SR 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="http://www.iaa.tu-bs.de/konmerz/gausseminar/">GAuS Seminar</a></div><br /><div class="event_speaker">Prof. Dr. Kouichi  Taira  (Ritsumeikan University)</div><div class="event_title">Essential self-adjointness of Klein-Gordon operators on asymptotically Minkowski spacetime <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 talk about essential self-adjointness(ESS) of Klein-Gordon operators on spacetimes which are perturbationsof Minkowski spacetime. ESS of differential operators has been studiedespecially for elliptic operators such as Laplace-Beltrami operatorsand Schrödinger operators. Here we focus on ESS for Klein-Gordonoperators which are not elliptic, where previous methods cannot beapplied. Moreover, it has an application to a construction of Feynmanpropagator in Quantum Field Theory. This is a joint work with ShuNakamura.</div><div class="event_time">13:00 &bull; Online via Zoom</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/mat770.1">Oberseminar: Algebraische Geometrie</a></div><br /><div class="event_speaker">Prof. Dr. Deepam Patel (Purdue University)</div><div class="event_title">K-theory of convergent power series, and enriched hodge structures <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\'ll discuss an enriched version of (mixed) Hodge structures and the existence of such structures on the cohomology of `links\', with the goal of understanding the algebraic K-theory of convergent power series rings via these new invariants. This is based on joint work with M. Nori and V. Srinivas.</div><div class="event_time">13:15 &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://www.math.uzh.ch/mat760">Ergodic theory and dynamical systems seminar</a></div><br /><div class="event_speaker">Dr. Prasuna Bandi (IHES)</div><div class="event_title">Hausdorff dimension of exact sets in Ahlfors regular spaces <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In Diophantine approximation, it is a classical problem to determine the size of the sets related to \\(\\psi\\) approximable set for a given non-increasing function \\(\\psi\\). Bugeaud determined the Hausdorff dimension of the exact \\(\\psi\\) approximable set answering a question posed by Beresnevich, Dickinson, and Velani. We compute the Hausdorff dimension of the exact set in the general setup of Ahlfors regular spaces. Our result applies to approximation by orbits of fixed points of a wide class of discrete groups of isometries acting on the boundary of hyperbolic metric spaces. This is joint work with Anish Ghosh and Debanjan Nandi.</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_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. Matthias Voigt (Fern Uni Schweiz)</div><div class="event_title"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Structure-Preserving Model Order Reduction of Dynamical Systems</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Model order reduction is a field of mathematics that deals with the complexity reduction of mathematical models in order to reduce the computational costs of tasks such as numerical simulation, optimization, or control. In this talk, first an overview of the field will be given and two of the classical systems theoretic reduction methods (balanced truncation and IRKA) will be reviewed. The second part of the presentation will focus on structure-preserving reduction methods for structured models. This includes a variant of balanced trunction for symmetric second-order systems and a rational fitting method for the class of port-Hamiltonian systems.</div><div class="event_time">17:15 &bull; Universität Bern, Sidlerstrasse 5, 3012 Bern, Lecture Room B6</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, May 9      </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"> Karoly Böröczky (Alfréd Rényi Institute of Mathematics)</div><div class="event_title">The Isoperimetric inequality, the Brunn-Minkowski theory, and the Lp Minkowski problem</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_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unine.ch/math/home/colloques_et_seminaires/seminaires-de-linstitut.html">Séminaire Groupes et Géométrie </a></div><br /><div class="event_speaker"> Corentin Bodart (Université de Genève)</div><div class="event_title">Intermediate geodesic growth in virtually nilpotent groups <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Geodesic growth counts the number of geodesics of length n in the Cayley graph of a group G (with a generating set S). As soon as the group has exponential volume growth, the geodesic growth is also exponential. Finding pairs (G,S) with polynomial geodesic growth is trickier but, by now, several constructions are known. At last, a question that has been around and open since the 90\'s is the existence of a pair (G,S) with intermediate geodesic growth. Most of the efforts to construct such an example have been centered on groups of intermediate volume growth, without success. Perhaps surprisingly, we show that intermediate geodesic growth is possible in the realm of virtually nilpotent groups.<br>In this talk, I will introduce our main example, a virtually 3-step nilpotent group, and a geometric model for it. I will explain the main ideas necessary for both the upper and lower bounds on the number of geodesics, and compare them with previous arguments of Shapiro, Bridson-Burillo-Elder-Sunic and Bishop-Elder.</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://algebra.dmi.unibas.ch/seminar.html">Seminar Algebra and Geometry</a></div><br /><div class="event_speaker"> Alicia Jaquet-Chiffelle (Universität Berlin & Université de Neuchâtel)</div><div class="event_title">An Algorithm for computing D-Weierstrass Places  <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Given a certain curve and a point P on this variety, we can look at the pole orders at P of functions defined on this curve. The set of all possible pole orders at P is surprisingly the same for all but finitely many points, namely Weierstrass points. My talk will be mainly based on an article by Florian Hess. His goal was to find an algorithm for computing Weierstrass points. More precisely, he obtained an algorithm for computing D-Weierstrass places. In my talk, I will start by introducing the concepts of algebraic geometry needed to understand the article. Then, I will define what D-Weierstrass places are and give the idea Florian Hess has for computing these places, that is using a link with linear systems. We will stop a while on this link which is a center point of his article and happens to have an error in its proof. Indeed, we have found a counter-example to one of the arguments used in his proof. We showed as well that his proof is correct if we added a new hypothesis. The proposition he states seems however correct in the general case as well, but no proof has been found up till now. Supposing the proposition is correct in the general case, I will then show how he uses this link to obtain an algorithm for computing D-Weierstrass places.</div><div class="event_time">10:30 &bull; Universität Basel, Spiegelgasse 5, SR 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/daco-seminar">DACO Seminar</a></div><br /><div class="event_speaker"><a class="external" href="https://susan.su.domains/">Prof. Dr. Susan Holmes (Stanford University)</a></div><div class="event_title">Generative models for power, identifiability and goodness of fit testing <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />By linking conceptual theories with observed data, generative models can support reasoning in complex situations.They have come to play a central role both within and beyond statistics, providing the basis for power analysis in molecular biology, theory building in particle physics, and resource allocation in epidemiology.This talk will survey some applications of modern generative models and show how they inform experimental design, iterative model refinement, goodness-of-fit evaluation, and agent based simulation. We emphasize a modular view of generative mechanisms and discuss how they can be flexibly recombined in new problem contexts.Current research in generative models is currently split across several islands of activity, and we highlight opportunities lying at disciplinary intersections.This is joint work with Kris Sankaran that was recently published and for which practical illustrations are  available at https://github.com/krisrs1128/generative_review.  </div><div class="event_time">14:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</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://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"> Stéphane Lamy (Université de Toulouse)</div><div class="event_title">Tits alternative for the Cremona group <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A group G satisfies the Tits alternative if any subgroup contains either a free group over 2 generators, of a solvable group of finite index.The classical result by Jacques Tits is that the linear groups satisfy this alternative, up to restricting to finitely generated subgroups in the case of a ground field of positive characteristic.  In this talk I will explain the strategy of proof to show that the plane Cremona group also satisfies the Tits alternative.It will essentially be a survey of previous results by Cantat and Urech, with a few contributions by myself mainly for the case of positive characteristic, and also for the classification of torsion subgroups.</div><div class="event_time">14:15 &bull; EPF Lausanne, Salle GR A3 32</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">Prof. Dr. Costante  Bellettini (University College London)</div><div class="event_title">Hypersurfaces with mean curvature prescribed by an ambient function <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let N be a compact Riemannian manifold of dimension 3 or higher, and g a Lipschitz non-negative (or non-positive) function on N. In joint works with Neshan Wickramasekera we prove that there exists a two-sided (well-defined global unit normal) closed hypersurface M whose mean curvature attains the values prescribed by g. Except possibly for a small singular set (of codimension 7 or higher), the hypersurface M is C^2 immersed; more precisely, the immersion is a quasi-embedding, namely the only non-embedded points are caused by tangential self-intersections (around such a non-embedded point, the local structure is given by two disks, lying on one side of each other, and intersecting tangentially, as in the case of two spherical caps touching at a point). A special case of PMC (prescribed-mean-curvature) hypersurfaces is obtained when g is a constant, in which case the above result gives a CMC (constant-mean-curvature) hypersurface for any prescribed value of the mean curvature. The proof employs an Allen--Cahn approximation scheme, classical minmax, and gradient flow arguments. A key issue in the construction (and, more generally, in related compactness questions) is the possible formation of "hidden boundaries".</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://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.math.uzh.ch/mat075.1">Zurich Graduate Colloquium</a></div><br /><div class="event_speaker">Alessio Cela (ETHZ)</div><div class="event_title">What is... Gromov-Written theory? <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The most basic question in enumerative Geometry is: How many lines are there through two distinct points? A natural extension of this question is to count the number Nd of rational curves of degree d passing through 3d-1 points in general position in the complex projective plane. I will explain how to formulate this problem using Gromov-Witten theory and Kontsevich solution to the problem in terms of a recursive formula which reduces the question to the computation of N1 = 1.</div><div class="event_time">16:15 &bull; UZH Zentrum, Building KO2, Room F 150</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"> Danica Kosanovic (ETH Zürich)</div><div class="event_title">2-knots with light bulbs and knotted families of arcs <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Knowing when one can embed a surface into a 4-manifold is a question of fundamental importance for 4-manifold theory. It gives rise to a field of 2-knot theory, which is in a certain sense even harder than classical knot theory. However, in some situations – like in the setting when embedded surfaces (disks) have a common “light bulb” (in the boundary) – one can completely classify them up to isotopy. I will explain how in joint work with Peter Teichner we provide such a classification using some fairly general techniques from homotopy theory, leading to surprising applications of higher homotopy groups of spaces of embeddings.</div><div class="event_time">17:00 &bull; Université de Neuchâtel, Rue Emile Argand 11, Auditoire B013</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, May 10      </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"> Shahar Mendelson (The Australian National University)</div><div class="event_title">Probabilistic methods in Analysis</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_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">Prof. Dr. Dhruv Ranganathan (Cambridge University)</div><div class="event_title">Brill-Noether theory for curves in an algebraic torus <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Brill-Noether theory is a rich subject dating back to the late 19th century. It governs the geometry of the space of maps from curves to projective space, such as the dimensions of its irreducible components and the dimensions of their images in the moduli space of curves. Logarithmic geometry suggests an alternative geometry: the space of rational maps from smooth pointed curves to an algebraic torus, known in some circles as the interior of the higher double ramification cycle. I will explain how to use logarithmic and tropical techniques to gain access to the geometry of this space, and prove “Brill-Noether existence” results. These specialise in a transparent fashion to classical results of Kempf, Kleiman, Laksov, as well as the recent Hurwitz-Brill-Noether direction pioneered by K. Cook-Powell, E. Larson, H. Larson, D. Jensen, and I. Vogt. The talk is based on work with D. Jensen. </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_default">Universit&auml;t Neuchatel</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">Eda Kirimli (University of Bristol and Université de Neuchâtel)</div><div class="event_title">Isogeny Graphs of Abelian Surfaces <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Isogeny-based cryptography is an active research area in post-quantum cryptography, and its security depends on variants of isogeny problems, namely the problem of finding an explicit isogeny between two abelian varieties. Although much of the research focused on isogenies of elliptic curves so far, it is mathematically interesting to understand isogeny graphs in dimension 2 in full generality, and the recent attacks using isogenies in higher dimensions switched the attention to dimension 2 more than ever. Unlike known methods, we use very geometrical and arithmetical objects called Refined Humbert Invariants defined by Kani. We will propose possible promising applications using Refined Humbert Invariants of abelian surfaces. We will investigate how to understand isogeny graphs of abelian varieties, and explain possible applications such as determining minimum walks, finding split abelian surfaces, a security reduction to computing the degree of an isogeny, and multilinear maps. This is a joint work in progress with Harun Kir. &lt;BR> &lt;BR> (**This eSeminar will take place over Zoom, using the same meeting details as previous seminars. If you do not have meeting details, please contact zita.fiquelideabreu@math.uzh.ch **)</div><div class="event_time">15:00 &bull; Uni Neuchatel, E213</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"><a class="external" href="https://math.ethz.ch/people/dsemola">Dr. Daniele Semola (ETH Z&uuml;rich, Switzerland)</a></div><div class="event_title">Fundamental Groups and the Milnor Conjecture <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />It was conjectured by John Milnor in 1968 that the fundamental group of a complete Riemannian manifold with non negative Ricci Curvature is finitely generated. I will present recent joint work with Elia Bruè and Aaron Naber where we construct a complete 7-dimensional Riemannian manifold with nonnegative Ricci Curvature and infinitely generated fundamental group, thus providing a counterexample to the Milnor conjecture.</div><div class="event_time">15:45 &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/sam/news-and-events/zhacm-colloquia">Zurich Colloquium in Applied and Computational Mathematics</a></div><br /><div class="event_speaker"><a class="external" href="https://www.polito.it/en/staff?p=silvia.falletta">Prof. Dr. Silvia Falletta (Politecnico di Torino)</a></div><div class="event_title">Solving 2D linear elastic wave equations via scalar potentials   <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Soft tissues and other nearly incompressible media pose a challenge for simulating elastic wave propagation, due to the slow propagation of shear waves compared to pressure waves. To overcome this challenge, a classical Helmholtz-Hodge decomposition is used to split the displacement field into scalar pressure (P -) and shear (S-) waves, allowing for separate treatment of the two dynamics and the construction of discretization spaces suited for each type of wave. This presentation focuses on the simulation of 2D soft scattering elastic wave propagation in isotropic homogeneous media, using the scalar potential decomposition in the time-harmonic regime. For problems defined in bounded domains, a Virtual Element Method (VEM) with varying mesh sizes and degrees of accuracy is proposed to approximate the two scalar potentials. For unbounded domains, a boundary element method is coupled with the VEM. The proposed approach performs better than standard methods that directly use the vector formulation, as it allows for tracking the different wave numbers associated with P - and S-speeds of propagation. This makes it possible to use a high-order method for the approximation of waves with higher wave numbers. We establish the stability of our method and present a convergence error estimate in the L2-norm for the displacement field. Notably, our estimate separates the contributions to the error associated with the P - and S- waves. We provide numerical results to demonstrate the effectiveness of the proposed approach.This presentation is the result of collaborative work with M. Ferrari and L. Scuderi from the Polytechnic University of Turin.</div><div class="event_time">16:30 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 35/36</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_default">Universit&auml;t Neuchatel</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">Hermann Tchatchiem Kamche (University of Yaounde)</div><div class="event_title">Low-Rank Parity-Check Codes Over Finite Commutative Rings <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Low-Rank Parity-Check (LRPC) codes are a class of rank metric codes that have many applications specifically in network coding and cryptography. Recently, LRPC codes have been extended to Galois rings which are a specific case of finite rings. In this talk, we first define LRPC codes over finite commutative local rings, which are bricks of finite rings, with an efficient decoder. We improve the theoretical bound of the failure probability of the decoder. Then, we extend the work to arbitrary finite commutative rings. Certain conditions are generally used to ensure the success of the decoder. Over finite fields, one of these conditions is to choose a prime number as the extension degree of the Galois field. We have shown that one can construct LRPC codes without this condition on the degree of Galois extension. &lt;BR> &lt;BR> (**This eSeminar will take place over Zoom, using the same meeting details as previous seminars. If you do not have meeting details, please contact zita.fiquelideabreu@math.uzh.ch **)</div><div class="event_time">16:30 &bull; Uni Neuchatel, E213</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/seminar-on-stochastic-processes">Seminar on Stochastic Processes</a></div><br /><div class="event_speaker">Prof. Dr. Cyril Marzouk (École polytechnique)</div><div class="event_title">Scaling limits of random maps with prescribed face degrees <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Random planar maps are toy models in random geometry that allow to easily define discrete random surfaces. One hope that when letting the number of faces tend to infinity and their size to zero at the correct speed, one can get a continuum random surface, in the same way Brownian motion arises from large random walks. A decade ago, after a series of works by different authors, the convergence of random quadrangulations and a few other models to the so-called Brownian map was finally obtained simultaneously by Le Gall and Miermont. In this talk we will discuss the more general model of maps sampled uniformly at random given their face degrees and will discuss the convergence depending on these degrees.</div><div class="event_time">17:15 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room  H12</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Thursday, May 11      </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"> Brita Nucinkis (Royal Holloway, University of London)</div><div class="event_title">Cohomological methods in group theory</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_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"> Roland van der Veen (Bernoulli Institute, University of Groningen)</div><div class="event_title">Twisting quantum knot invariants <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />After giving an elementary introduction to quantum knot invariants we will show how one can twist this construction to allow a representation of the knot group. Some existing invariants such as the twisted Alexander polynomial and the ADO invariant are of this type and use Hopf algebraic techniques to show the degree of the invariant is related to the genus of the knot. This is joint work with Daniel Lopez Neumann, see https://arxiv.org/abs/2211.15010.</div><div class="event_time">13:15 &bull; Université de Genève, Conseil Général 7-9, Room 1-15</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"> Michel Van Garrel (University of Birmingham)</div><div class="event_title">Geometry of Enumerative Mirror Symmetry <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />For the pair (Y,D) of a smooth Fano variety and smooth anticanonical divisor, mirror symmetry computes in a complicated fashion the counts of rational curves in Y that meet D in one point only (rather, the corresponding log Gromov-Witten invariants). In this talk, I will show how these computations are in fact the consequence of a simple geometric duality between (Y,D) and its Gross-Siebert intrinsic mirror family. I will focus on the case of Y the projective plane and D an elliptic curve. Then the mirror family is the moduli space of ellipt</div><div class="event_time">13:15 &bull; EPF Lausanne, Salle MA A3 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/sfs/news-and-events/data-science-seminar">ETH-FDS seminar </a></div><br /><div class="event_speaker"> Stephan Mandt  (University of California)</div><div class="event_title">Deep Latent Variable Models for Compression and Natural Science <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Latent variable models have been an integral part of probabilistic machine learning, ranging from simple mixture models to variational autoencoders to powerful diffusion probabilistic models at the center of recent media attention. Perhaps less well-appreciated is the intimate connection between latent variable models and data compression, and the potential of these models for advancing natural science. This talk will explore these topics. I will begin by showcasing connections between variational methods and the theory and practice of neural data compression. On the applied side, variational methods lead to machine-learned compressors of data such as images and videos and offer principled techniques for enhancing their compression performance, as well as reducing their decoding complexity. On the theory side, variational methods also provide scalable bounds on the fundamental compressibility of real-world data, such as images and particle physics data. Lastly, I will also delve into climate science projects, where a combination of deep latent variable modeling and vector quantization enables assessing distribution shifts induced by varying climate models and the effects of global warming. Short Bio:Stephan Mandt is an Associate Professor of Computer Science and Statistics at the University of California, Irvine. From 2016 until 2018, he was a Senior Researcher and Head of the statistical machine learning group at Disney Research in Pittsburgh and Los Angeles. He held previous postdoctoral positions at Columbia University and Princeton University. Stephan holds a Ph.D. in Theoretical Physics from the University of Cologne in Germany, where he received the National Merit Scholarship. He received the NSF CAREER Award, a Kavli Fellowship of the U.S. National Academy of Sciences, the German Research Foundation\'s Mercator Fellowship, and the UCI ICS Mid-Career Excellence in Research Award. He is a member of the ELLIS Society and a former visiting researcher at Google Brain. Stephan will serve as Program Chair of the AISTATS 2024 conference, currently serves as an Action Editor for JMLR and TMLR, and frequently serves as Area Chair for NeurIPS, ICML, AAAI, and ICLR. </div><div class="event_time">16:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room D 1.2</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/events/mathematics-colloquia/">Mathematics Colloquium </a></div><br /><div class="event_speaker"> Isabelle Gallagher (Ecole Normale Supérieure de Paris)</div><div class="event_title">On the dynamics of dilute gases <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The evolution of a gas can be described by different models depending on the scale of observation. A natural question, raised by Hilbert in his sixth problem, is whether these models provide consistent predictions. In the case of gases of hard spheres, Lanford showed in 1974 that the Boltzmann equation appears as a law of large numbers in the low density limit, at least for very short times. In this talk we will present Lanford\'s result, and some more recent extensions to understand fluctuations and large deviations around the Boltzmann equation.<br><br>Please resister on the following form : https://forms.gle/z8a1iGQvtjy6eFYC6</div><div class="event_time">16:15 &bull; EPF Lausanne, Salle CM 1 5</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/colloque">Colloque de Mathématiques </a></div><br /><div class="event_speaker"> Dustin Clausen (University of Copenhagen)</div><div class="event_title">A modified Hodge conjecture <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Hodge conjecture, for a smooth projective variety over the complex numbers, gives a criterion on a cohomology class for it to be realized by algebraic cycles. But who knows --- maybe it\'s false! I will give an introduction to the Hodge conjecture, and then propose a modification, stronger in some ways and weaker in others, which is hopefully easier to prove. This is based on joint work with Peter Scholze.</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://www.math.uzh.ch/mat675.1">PDE and Mathematical Physics</a></div><br /><div class="event_speaker">Dr. Emanuela Giacomelli (LMU)</div><div class="event_title">On the low density Fermi gas in three dimensions <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In recent decades, the study of many-body systems has been an active area of research in both physics and mathematics. In this talk, we will consider a system of N spin 1/2 interacting fermions confined in a box in the dilute regime, with a particular focus on the correlation energy which is defined as the difference between the ground state energy and that of the free Fermi gas. We will discuss some recent results about a first order asymptotics for the correlation energy in the thermodynamic limit where the number of particles and the size of the box are sent to infinity keeping the density fixed. In particular, we will present a new upper bound for the correlation energy, which is consistent with the well-known Huang-Yang formula from 1957.</div><div class="event_time">16:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</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://www.ntwebseminar.org/">Number Theory Web Seminar</a></div><br /><div class="event_speaker"> Ben Green (University of Oxford)</div><div class="event_title"><a class="external" href="https://www.ntwebseminar.org/">On Sarkozy\'s theorem for shifted primes</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Suppose that N is large and that A is a subset of {1,..,N} which does not contain two elements x, y with x - y equal to p-1, p a prime. Then A has cardinality at most N^{1 - c}, for some absolute c > 0. I will discuss the history of this kind of question as well as some aspects of the proof of the stated result. </div><div class="event_time">17:00 &bull; Universität Basel, online Seminar</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"><a class="external" href="https://personal.ntu.edu.sg/ariel.neufeld/">Prof. Dr. Ariel Neufeld (Nanyang Technological University, Singapore)</a></div><div class="event_title">Quantum Monte Carlo algorithm for solving Black-Scholes PDEs for high-dimensional option pricing in finance and its proof of overcoming the curse of dimensionality <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 first provide a brief introduction to quantum computing from a mathematical perspective. No prior knowledge of quantum computing is necessary. We then introduce a quantum Monte Carlo algorithm to solve high-dimensional Black-Scholes PDEs with correlation for high-dimensional option pricing. The payoff function of the option is of general form and is only required to be continuous and piece-wise affine (CPWA), which covers most of the relevant payoff functions used in finance. We provide a rigorous error analysis and complexity analysis of our algorithm. In particular, we prove that the computational complexity of our algorithm is bounded polynomially in the space dimension d of the PDE and the reciprocal of the prescribed accuracy &#949; and so demonstrate that our quantum Monte Carlo algorithm does not suffer from the curse of dimensionality. This talk is based on a joint work with Yongming Li.</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, May 12      </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_nolink">Talks in Mathematical Finance </a></div><br /><div class="event_speaker"> Marcin Kacperczyk (Imperial College London )</div><div class="event_title">Carbon Transition Risk and Net-Zero Portfolios <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We study the impact of net-zero carbon portfolios on the cross section of stock returns globally. We find that companies that face a bigger threat of being removed from the portfolios generate higher expected returns and have lower values. The results hold for both intensive and extensive margin of portfolio holdings and are robust to different choices of screening decision and measurements.</div><div class="event_time">10:30 &bull; EPF Lausanne, UniL campus, Extranef 126</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"> Martin Eigel (WIAS Berlin)</div><div class="event_title">Title T.B.A.</div><div class="event_time">11:00 &bull; Universität Basel, Spiegelgasse 5, SR 05.002</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"> Moritz Jirak (Universität Wien)</div><div class="event_title">Weak dependence and optimal quantitative self-normalized central limit theorems <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Consider a stationary, weakly dependent sequence of random variables.<br>Given that a CLT holds, how should we estimate the long-run variance? This problem has been studied for decades, prominent proposed solutions were given for instance by Andrews (1991) or Newey and West (1994). Using the proximity of the corresponding normal distribution as quality measure, we discuss optimalsolutions and why previous proposals are not optimal in this context.<br>The setup contains many prominent dynamical systems and time series models, including random walks on the general linear group, products of positive random matrices, functionals of Garch models of any order, functionals of dynamical systems arising from SDEs, iterated random functions and many more.</div><div class="event_time">11:15 &bull; EPF Lausanne, Salle CE 1 105 </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="https://www.unine.ch/math/home/colloques_et_seminaires/seminaires-de-linstitut.html">Séminaire de Géométrie et Systèmes dynamiques </a></div><br /><div class="event_speaker"> Michel van Garrell (University of Birmingham)</div><div class="event_title">From symplectic to algebraic geometry <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Proofs in symplectic geometry quickly become intangible due to the difficulties of dealing with partial differential equations. Mirror symmetry proposes a solution to this by turning symplecto-geometric objects into their algebro-geometric counterparts, for which the power of algebra can be usefully leveraged. At its most basic, this is based on the duality between co-characters, which we make think of as symplectic discs in a torus, and characters, which give a basis of functions on the dual torus. I will develop this idea to give an introduction to mirror symmetry, which is the study of the symplectic geometry of a manifold via the complex algebraic geometry of its mirror manifold.</div><div class="event_time">13:00 &bull; Université de Neuchâtel, Rue Emile-Argand 11, Room B217</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">Prof. Dr. Louis Jeanjean  (Université de Franche-Comté)</div><div class="event_title">Normalized solutions of mass-supercritical NLS equations on compact metric graphs <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 shall consider the existence of non-trivial bound states of prescribed mass for the mass-supercritical nonlinear Schrödinger equation on compact metric graphs. The investigation is based upon a general variational principle which combines the monotonicity trick and a min-max theorem with second order information, and upon the blow-up analysis of bound states with prescribed mass and bounded Morse index.If times permit, we shall also discuss some extensions to non-compact graphs.This talk relies on joint works with Jack Borthwick (University of Franche-Comté), Xiaojun Chang (Northeast Normal University) and Nicola Soave (Politecnico di Milano).</div><div class="event_time">14:15 &bull; EPF Lausanne, Salle BS 270  </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"> Shahar Mendelson (Australian National University)</div><div class="event_title">Structure preservation via the Wasserstein distance (joint work with D. Bartl) <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Consider an isotropic measure \\mu on R^d (i.e., centred and whose covariance is the identity) and let X_1,...,X_m be independent, selected according to \\mu. If \\Gamma=m^{-1/2} \\sum_{i=1}^m &lt;X_i,->e_i is the random operator whose rows are X_i/\\sqrt{m}, how does the random set \\Gamma S^{d-1} typically look like? For example, if the extremal singular values of \\Gamma are close to 1, then \\Gamma S^{d-1} is "well approximated" by a d-dimensional section of S^{m-1} and vice-versa. But is it possible to give a more accurate description of that set?I will show that under minimal assumptions on \\mu, with high probability and uniformly in t \\in S^{d-1}, each vector \\Gamma t  inherits the structure of the one-dimensional marginal &lt;X,t> in a strong sense. <br>If time permits I will also outline what happens when considering an arbitrary subset of S^{d-1} rather than the entire sphere. </div><div class="event_time">15:15 &bull; EPF Lausanne, Salle CM 1 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" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Sam Molcho (ETH Zürich)</div><div class="event_title">Grothendieck-Riemann-Roch for twisted bundles <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Brill-Noether classes w_{g,d}^r are virtual fundamental classes associated to the Brill-Noether loci W_{g,d}^r in the universal Jacobian Pic^d(C_{g,n}/M_{g,n}), parametrizing curves with line bundles that have at least r+1 linearly independent sections. Pulling back to M_{g,n} via Abel-Jacobi sections produces tautological classes, which can be calculated by Grothendieck-Riemann-Roch. Extending those classes to the compactification \\bar{M}_{g,n} is however not straightforward: the right extensions live naturally on blowups of \\bar{M}_{g,n}, or, equivalently, in logCH(\\bar{M}_{g,n}). Consequently, their calculation is also subtle. In this talk, I will discuss a general formula that allows to calculate these classes. The formula is close in the spirit of Mumford\'s GRR calculation, but with combinatorial corrections required. I will then discuss the connection of the calculation with relations in the tautological ring, to the limited extent that I understand them. This is joint work with Alex Abreu and Nicola Pagani.   </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>    </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>';