var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-19"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-17"><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. 4</span>      <span style="float: right; text-align:right; width: 250px;">11.3 - 15.3.2024</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Spring Semester 2024</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, March 11      </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"> Matteo Nesi (University of Basel)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde/detail/bernoullis-tafelrunde-matteo-nesi-university-of-basel/">Riemann\'s Uniformization Theorem</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p><a href="https://dmi.unibas.ch/fileadmin/user_upload/dmi/Studium/Mathematik/Bernoullis_Tafelrunde/matteo_nesi1.pdf" target="_blank">abstract</a>&lt;/p></div><div class="event_time">12:15 &bull; Universität Basel, Seminarraum 05.002</div>        </div>        <div class="day_content_item important"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Prof. Dr. Ran Tessler (Weizmann Institute)</div><div class="event_title">The amplituhedron: tilings and cluster adjacency <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The amplituhedron is a geometric object discovered by Arkani-Hamed and Tranka (2013) in their study of planar N=4 Super Yang Mills scattering amplitudes.In my talk I will describe this object, its properties, and the recent resolutions of two major conjectures in the field: the BCFW triangulation conjecture and the cluster adjacency conjecture for BCFW tiles. Based on joint works with C. Even-Zohar, T. Lakrec, M. Parisi, M. Sherman-Bennett and L. Williams.</div><div class="event_time">15:00 &bull; ETH Zentrum, Building ITS, Room  </div>        </div>        <div class="day_content_item cancelled"><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"> Xiuxong Chen (SUNY Stony Brook USA and ShanghaiTech University China)</div><div class="event_title">CANCELLED: Title T.B.A.</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"> Jean Barbier (ICTP)</div><div class="event_title">A multi-scale cavity method, with application to sub-linear rank matrix denoising <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The cavity method is a powerful approach from the mathematical physics of spin glasses allowing to rigorously tackle the computation of log-partition functions and order parameters in mean-field spin models. I will present a generalization which allows to treat models where the variables are not simple finite-dimensional spins but are instead matrices whose dimensions M,N both grow in the thermodynamic limit; this in contrast with standard spin models where only one parameter, the number N of variables in the system, grows large. I will present the method in the context of an inference problem known as matrix denoising, in the challenging regime where the matrix to infer has a rank M (slowly) growing with its size N.</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. Tobias Harz (Plurisubharmonic defining functions for pseudoconvex domains)</div><div class="event_title"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Plurisubharmonic defining functions for pseudoconvex domains</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Complex analysis investigates functions of complex numbers, in particular holomorphic functions. What kind of holomorphic functions can be constructed on a given domain, depends heavily on properties of the domain, especially in dimensions larger than 1. Therefore, many questions in the analysis of several complex variables are not concerned directly with holomorphic functions, but instead with properties of special classes of domains, the so-called pseudoconvex domains.Many of the relevant properties pseudoconvex domains have, or can have, are formulated with a potential-theoretic conception, in particular in terms of so-called plurisubharmonic functions. For example, a domain in complex Euclidean space is pseudoconvex, by definition, if it admits a plurisubharmonic exhaustion function.In this talk we will discuss some of the basic results from the analysis of several complex variables, introduce the notions of pseudoconvex domains and plurisubharmonic functions, and briefly discuss the question of existence of plurisubharmonic defining functions for pseudoconvex domains.</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, March 12      </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"> Murray Elder (University of Technology Sidney)</div><div class="event_title">ome properties of multiple context-free languages <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will explain what multiple context-free languages are, giving both grammar and machine (informal) definitions.I will then explain a new \\emph{swapping lemma} for proving that a language is not multiple context-free, and apply it to some examples, including the word problem of $F_2\\times \\mathbb Z$. I will also explain our result that \\emph{permutation closure} of a multiple context-free is multiple context-free, which complements work of Brandst\\"adt (resp. Brough \\emph{et al.}) who showed  the same result for regular, context-sensitive, recursively enumerable (resp. EDT0L and ET0L) languages.Both results exploit the machine definition.</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_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"> Amal Machtalay (EPFL)</div><div class="event_title">Space-Time discretization of traffic flow Mean-field game model <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We explore a multi-class traffic model and examine the computational feasibility of mean-field games (MFG) in obtaining approximate Nash equilibria for traffic flow games involving a large number of vehicles. The obtained MFG system is challenging for different reasons, among them, the non-smoothness of the solutions, the high nonlinearity of the MFG system in addition to the large-scale computations.</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_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"> Ilaria Viglino</div><div class="event_title">Almost sure convergence of least common multiple of ideals for polynomials over a number fields <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />For f an irreducible polynomial with integer coefficients of degree n, Cilleruelo\'sconjecture states that log(lcm(f(1),...,f (M))) is asymptotic to (n - 1)M log M, as M tends to infinity. The Prime Number Theorem for arithmetic progressions can be exploited to obtain an asymptotic estimate when f is a linear polynomial. Cilleruelo extended this result to quadratic polynomials. The asymptotic remains unknown for irreducible polynomials of higher degree. Recently the conjecture was shown on average for a large family of polynomials of any degree by Rudnick and Zehavi. We investigate the case of S_n-polynomials with coefficients in the ring of algebraic integers of a fixed number field extension K/Q by considering the least common multiple of ideals in the ring of algebraic integers.</div><div class="event_time">14:15 &bull; EPF Lausanne, MA A1 10</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"> Pierre Bieliavsky (Université catholique de Louvain)</div><div class="event_title">New classes of locally compact quantum groups <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Locally compact quantum groups (LCQG) were introduced in the beginning of the century by S. Vaes and J. Kustermans as a von Neumann (i.e. measurable) version of quantum groups in the context of operator algebra. Since then the theory has been widely developed.  However, it appears that, besides compact quantum groups, the theory suffers from a lack of new non-compact examples.  In a joint work with V. Gayral, S. Neyshveyev and L. Tuset, we constructed non-formal deformation quantizations of Lie group of Fröbenius type which provide classes of Lie group based examples. The construction is mainly geometrical. In the talk, I will first introduce the notion of locally compact quantum group and then explain the construction. I will also discuss some open questions in that context.</div><div class="event_time">15:30 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</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/mathicse/">Computational Science and Engineering </a></div><br /><div class="event_speaker"> Frederike Duembgen (Université de Toronto)</div><div class="event_title">Solving hard problems in robotics – with a little help from semidefinite relaxations, nullspaces, and sparsity <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br /> Many state estimation and planning tasks in robotics are formulated as non-convex optimization problems, and commonly deployed efficient solvers may converge to poor local minima. Recent years have seen promising developments in so-called certifiably optimal estimation, showing that many problems can in fact be solved to global optimality or certified through the use of tight semidefinite relaxations. In this talk, I present our efforts to make such methods – for the field of state estimation in particular – more practical for roboticists. Among those efforts, I will present novel efficient optimality certificates as a low-cost add-on to off-the-shelf local solvers, which apply to a variety of problems including range-only, stereo-camera and, more generally, matrix-weighted localization. Then, I present our approach to automatically certify almost any state estimation problem, using a sampling-based method to automatically find tight relaxations through nullspace characterizations. I end with an overview of our most recent work, which allows to create both fast and certifiably optimal solvers by exploiting the sparse problem structure. </div><div class="event_time">16:15 &bull; EPF Lausanne, CM 1517</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">Segev Gonen Cohen (ETHZ)</div><div class="event_title">What is... Hilbert\'s 17th problem? <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />\'\'Suppose that we are given a polynomial which can be expressed as a sum of squares of polynomials with real coefficients, for example f(X,Y,Z) = (X-4Y)^2 + (17Z^3 - 4XYZ)^2. Then it is clear that no matter what (real) inputs we put in, we will get something positive. Minkowski, in his PhD defence, asked about the converse - suppose we have a polynomial that takes only positive values, must this be because it is a sum of squares? Hilbert, who was sat in the audience, realised that the answer is no; but modified the question slightly, and famously included it as the 17th in a list of open problems presented at the 1900 ICM in Paris. The main part of this talk will be devoted to the solution to this problem, relying on some algebraic foundations of Artin, and a nice model-theoretic proof due to Robinson. Time permitting we will look at modern day generalisations of this question, partial solutions, and (depending on audience interest) their applications to the Connes Embedding Problem, Kazhdan\'s Property (T), norm computability, and more. No knowledge of any of these topics will be assumed.</div><div class="event_time">16:30 &bull; UZH Zentrum, Building KO2, Room F 150</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, March 13      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_fr"><a class="external" href="https://www.unifr.ch">Université de Fribourg</a></div><div class="event_type"><a class="external" href="https://commonweb.unifr.ch/_Science/Math/Pub/Math/seminars/OSgeom-top.html">Oberseminar Geometrie</a></div><br /><div class="event_speaker"> Sami Douba (IHES Paris)</div><div class="event_title">Systoles of hyperbolic hybrids <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We exhibit in any dimension n > 2 and for any positive integer m acollection of m pairwise incommensurable closed hyperbolic n-manifoldsof the same volume each possessing a unique shortest closed geodesic ofthe same length less than 1/m.</div><div class="event_time">10:20 &bull; Université de Fribourg, room Phys 2.52</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"> Stefan Kebekus</div><div class="event_title">Differential forms on singular spaces <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This talk surveys extension theorems for differential forms on singular complex spaces and explains their use in the study of minimal varieties. We survey a number of applications, pertaining to classification and characterisation of special varieties, non-Abelian Hodge Theory in the singular setting, and quasi-étale uniformization.</div><div class="event_time">13:00 &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://www.math.uzh.ch/mat760">Ergodic theory and dynamical systems seminar</a></div><br /><div class="event_speaker">Prof. Dr. Martin Leguil (École polytechnique)</div><div class="event_title">Rigidity of u-Gibbs measures for certain Anosov diffeomorphisms of the 3-torus. <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We consider Anosov diffeomorphisms of the 3-torus $\\mathbb{T}^3$ which admit a partially hyperbolic splitting $\\mathbb{T}^3 = E^s \\oplus E^c \\oplus E^u$ whose central direction $E^c$ is uniformly expanded. We may consider the 2-dimensional unstable foliation $W^{cu}$ tangent to $E^c \\oplus E^u$, but also the 1-dimensional strong unstable foliation $W^u$ tangent to $E^u$. The behavior of $W^{cu}$ is reasonably well understood; in particular, such systems have a unique invariant measure whose disintegrations along the leaves of $W^{cu}$ are absolutely continuous: the SRB measure. The behavior of $W^u$ is less understood; we can similarly consider the class of measures whose disintegrations along the leaves of $W^u$ are absolutely continuous, the so-called u-Gibbs measures. It is well-known that the SRB measure is u-Gibbs; conversely, in a joint work with S. Alvarez, D. Obata and B. Santiago, we show that in a neighborhood of conservative systems, if the strong bundles $E^s$ and $E^u$ are not jointly integrable, then there exists a unique u-Gibbs measure, which is the SRB measure.</div><div class="event_time">13:30 &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_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. Ran Tessler (Weizmann Institute)</div><div class="event_title">Open FJRW theory in genus 0 and mirror symmetry <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We define the g=0 open FJRW theory for (W,G) where W is a Fermat polynomial and G is its maximal symmetry group. We calculate all disk invariants, and classify the wall crossing group. We prove mirror symmetry with Saito\'s B-model.Based on joint works with Mark Gross and Tyler Kelly.</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_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">Prof. Dr. Anna Florio (Université Paris Dauphine-PSL)</div><div class="event_title">Birkhoff attractor of dissipative billiards <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In a joint work with Olga Bernardi and Martin Leguil, we study the dynamics of dissipative convex billiards. In these billiards, the usual elastic reflection law is replaced with a new law where the angle bends towards the normal after each collision. For such billiard dynamics there exists a global attractor; we are interested in the topological and dynamical complexity of an invariant subset of this attractor, the so-called Birkhoff attractor, whose study goes back to Birkhoff, Charpentier, and, more recently, Le Calvez. We show that for a generic convex table, on one hand, the Birkhoff attractor is simple, i.e., a normally contracted submanifold, when the dissipation is strong; while, on the other hand, the Birkhoff attractor is topologically complicated and presents a rich dynamics when the dissipation is mild.</div><div class="event_time">14:45 &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_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/aa/?events">Neuchatel - St.Gallen - Zurich Seminar in Coding Theory and Cryptography</a></div><br /><div class="event_speaker">Mario Jung</div><div class="event_title">Construction of Linear Codes using Latin squares <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In our globalised and digitalised world, fast and error-free communication is very important. To ensure this, we use error-correcting codes which should always be more efficient and have a higher error-correcting capacity. In this thesis, we investigate two types of LDPC codes which are obtained from Latin squares. The first is based on orthogonal Latin squares and the second is formed using Steiner 2-designs generated by a Latin square. For each code there is a bipartite graph in which cycles can occur. Such cycles can negatively influence the decoding efficiency. To counteract this, we will see how to locate and analyse these cycles and how to remove them.</div><div class="event_time">15:15 &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://math.ethz.ch/s/geometry-seminar">Geometry Seminar</a></div><br /><div class="event_speaker"> Laura Marino (Institut de Mathématiques de Jussieu-Paris Rive Gauche)</div><div class="event_title">Gordian distance bounds from Khovanov homology <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Gordian distance u(K,K\') between two knots K and K\' is defined asthe minimal number of crossing changes needed to relate K and K\'. Theunknotting number of a knot K, a classical yet hard to compute knotinvariant, arises as the Gordian distance between K and the trivialknot.Several lower bounds for both invariants exist. A well-known bound forthe unknotting number is given by the Rasmussen invariant, which isextracted from Khovanov homology, a bigraded chain complex associated toa knot up to chain homotopy equivalence.In this talk, I will introduce a new lower bound for the Gordiandistance, \\lambda, coming from Khovanov homology. After introducing allthe relevant ingredients I will present some results about \\lambda. Inparticular, \\lambda turns out to be sharper than the Rasmussen invariantas a lower bound for the unknotting number. This is based on joint work with Lukas Lewark and Claudius Zibrowius.</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_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. Sergios Agapiou (University of Cyprus)</div><div class="event_title">A new way for achieving Bayesian nonparametric adaptation <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We will consider Bayesian nonparametric settings with functional unknowns and we will be interested in evaluating the asymptotic performance of the posterior in the infinitely informative data limit, in terms of rates of contraction. We will be especially interested in priors which are adaptive to the smoothness of the unknown function.In the last decade, certain hierarchical and empirical Bayes procedures based on Gaussian process priors, have been shown to achieve adaptation to spatially homogenous smoothness. However, we have recently shown that Gaussian priors are suboptimal for spatially inhomogeneous unknowns, that is, functions which are smooth in some areas and rough or even discontinuous in other areas of their domain. In contrast, we have shown that (similar) hierarchical and empirical Bayes procedures based on Laplace (series) priors, achieve adaptation to both homogeneously and inhomogeneously smooth functions. All of these procedures involve the tuning of a hyperparameter of the Gaussian or Laplace prior.After reviewing the above results, we will present a new strategy for adaptation to smoothness based on heavy-tailed priors. We will illustrate it in a variety of nonparametric settings, showing in particular that adaptive rates of contraction in the minimax sense (up to logarithmic factors) are achieved without tuning of any hyperparameters and for both homogeneously and inhomogeneously smooth unknowns. We will also present numerical simulations corroborating the theory. This is joint work with Masoumeh Dashti, Tapio Helin, Aimilia Savva and Sven Wang (Laplace priors) and Ismaël Castillo (heavy-tailed priors)</div><div class="event_time">16:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room E 1.2</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/seminar-on-stochastic-processes">Seminar on Stochastic Processes</a></div><br /><div class="event_speaker">Dr. Victor Rivero (CIMAT Guanajuato)</div><div class="event_title">Recurrent extensions and Stochastic Differential equations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In the 70\'s Itô settled the excursion theory of Markov processes, which is nowadays a fundamental tool for analyzing path properties of Markov processes. In his theory, Itô also introduced a method for building Markov processes using the excursion data, or by gluing excursions together, the resulting process is known as the recurrent extension of a given process. Since Itô\'s pioneering work the method of recurrent extensions has been added to the toolbox for building processes, which of course includes the martingale problem and stochastic differential equations. The latter are among the most popular tools for building and describing stochastic processes, in particular in applied models as they allow to physically describe the infinitesimal variations of the studied phenomena. In this work we answer the following natural question. Assume X is a Markov process taking values in R that dies at the first time it hits a distinguished point of the state space, say 0, which happens in a finite time a.s., that X satisfies a stochastic differential equation, and finally that X admits a recurrent extension, say Z,  is a processes that behaves like Z up to the first hitting time of 0, and for which 0 is a recurrent and regular state. If any, what is the SDE satisfied by Z? Our answer to this question allows us to describe the SDE satisfied by many Feller processes. We analyze various particular examples, as for instance the so-called Feller brownian motions and diffusions, which include their sticky and skewed versions, and also continuous state branching processes and spectrally positive Levy processes.  </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, March 14      </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"> Umut Çetin (London School of Economics)</div><div class="event_title">Mathematics of Market Microstructure</div><div class="event_time">10:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://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"> Annette Huber</div><div class="event_title">Transcendence of 1-periods <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />(joint work with G. Wüstholz) 1-periods are complex numbers obtained as path intervals of algebraic 1-forms on algebraic varieties over the field of algebraic numbers. The set contains famous numbers like 2pi i or values of log in algebraic numbers. They are a long-standing object of transcendence theory.We will explain a sharp transcendence criterion and describe more generally all linear relations between 1-periods. The proof uses the theory of 1-motives in an essential way, allowing us to reduce the question to the seminal Analytic Subgroup Theorem of Wüstholz.In the second half of the talk, we will discuss 1-motives in more detail. This leads to quantitive  versions of the theorem, i.e., formulas for the dimension of the space of periods of a given1-motive.</div><div class="event_time">14:15 &bull; EPF Lausanne, Bernoulli center, GA 3 34</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"> Ken’ichi  OSHIKA  (Gakushuin University)</div><div class="event_title">La métrique de tremblement de terre sur l’espace de Teichmüller <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />La déformation de tremblement de terre introduite par Thurston est une déformation d’une structure hyperbolique d’une surface qui est une généralisation de la déformation de Fenchel-Nielsen. Thurston a remarqué dans sa prépublication célèbre que cette déformation induit une métrique finslerienne sur l’espace de Teichmüller, mais il n’y avait aucune étude sérieuse de cette métrique jusqu’à récemment. Nous montrons que cette métrique est asymétrique et incomplète avec la même complétion que la métrique de Weil-Petersson, et qu’elle a une rigidité par rapport à l’action du groupe modulaire.Un travail en collaboration avec Yi Huang, Huping Pan et Athanase Papadopoulos.</div><div class="event_time">14:15 &bull; Université de Genève, Conseil Général 7-9, Room 1-15</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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/kolloquium">Perlen-Kolloquium</a></div><br /><div class="event_speaker"> Prof. Jean-Pierre Eckmann (Universität Genf)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/perlen-kolloquium-prof-jean-pierre-eckmann-universitaet-genf/">Tumbling Downhill along a Given Curve</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>A cylinder will roll down an inclined plane in a straight line. A cone will<br/> wiggle along a circle on that plane and then will stop rolling.<br/> We ask the inverse question: For which curves drawn on the inclined plane<br/> $\\real^2$ can one chisel a shape that will roll downhill following precisely<br/> this prescribed curve and its translationally repeated copies?<br/><br/> This is a nice, and easy to understand problem, but the solution is quite<br/> interesting.<br/><br/> (Based on work mostly with Y. Sobolev and T. Tlusty. After a Nature paper,<br/> Solid-body trajectoids shaped to roll along desired pathways, August 2023.)&lt;/p></div><div class="event_time">16:15 &bull; Universität Basel, Spiegelgasse 5, Raum 05.002</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/mat675.1">PDE and Mathematical Physics</a></div><br /><div class="event_speaker">Dr. Simon Becker (ETH Zürich)</div><div class="event_title">Magic moire materials with a twist <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will review the mathematical analysis behind two classes of new exciting materials: Twisted bilayer graphene (TBG) and twisted semiconductors (TMDs) with an emphasis on their mathematical properties and differences. If time permits I will discuss results on these models under disorder. Joint work with Maciej Zworski Izak Oltman Martin Vogel and Mengxuan Yang</div><div class="event_time">16:15 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 46</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. Brandon Garcia Flores (Université de Lausanne)</div><div class="event_title">Optimal reinsurance from an optimal transport perspective <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We regard the optimal reinsurance problem as an iterated optimal transport problem between a (known) initial distribution and an (unknown) resulting risk exposure of the insurer. We also provide conditions that allow to characterize the support of optimal treaties, and show how this can be used to deduce the shape of the optimal contract, reducing the task to a finite-dimensional optimization problem, for which standard techniques can be applied. The proposed approach provides a general framework that encompasses many reinsurance problems, which we illustrate in several concrete examples, providing alternative proofs of classical optimal reinsurance results as well as establishing new optimality results, some of which contain optimal treaties that involve external randomness. Finally, we explain how in the current framework one can approach the problem of moral hazard in reinsurance and provide characterizations that avoid it.</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, March 15      </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/mpseminar/seminar.html">Séminaire de Mathématique Physique </a></div><br /><div class="event_speaker"> Pietro Longhi (Uppsala University)</div><div class="event_title">Quiver structures of knot invariants, open strings, and recursion <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Generating series of HOMFLYPT polynomials colored by symmetric representations have been found to coincide with partition functions of motivic Donldson-Thomas invariants of symmetric quivers, after a suitable identification of variables. I will discuss an interpretation of this relation based on string theory, where quivers encode interactions of M2 branes mediated by an M5 brane. Invariance of this picture under deformations leads to a generalization of the knots-quivers correspondence corroborated by wall-crossing type phenomena associated with skein relations among M2 brane boundaries. A generalization to skein valued curve counts, corresponding to counts of M2 on a stack with multiple M5 branes, will be discussed. Based on joint works with Ekholm and Kucharski and ongoing work with Ekholm and Nakamura.</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_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"> Federico Glaudo (IAS & Princeton University)</div><div class="event_title">Besicovitch 1/2 Conjecture and Linear Programming <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In 1928 Besicovitch formulated the following conjecture: if E is a Borel subset of the plane with finite length and its length is more than 1/2 of its diameter in all sufficiently small disks centered at its points, then E is rectifiable.The value 1/2 cannot be lowered and Besicovitch himself showed that the statement holds if 1/2 is replaced by 3/4. His bound was improved by Preiss and Tiser in the nineties to ~0.732. In this talk, I will report on further progress stemming from a joint work with Camillo De Lellis, Annalisa Massaccesi, and Davide Vittone. Besides improving substantially the bound of Preiss and Tiser, our work uncovers a connection with a class of linear programming problems. </div><div class="event_time">14:15 &bull; EPF Lausanne, MA B1 11</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/number-theory-seminar">Number Theory Seminar</a></div><br /><div class="event_speaker">Dr. Rosa Winter (King\'s College London)</div><div class="event_title">Weak weak approximation for del Pezzo surfaces of degree 2 <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Del Pezzo surfaces are classified by their degree d, and integer between 1and 9. The lower the degree, the more arithmetically complex these surfaces are. It is generally believed that, if a del Pezzo surface has one rational point, then it has many, and that they are well-distributed. After giving an overview of different notions of ‘many’ rational points and what is known so far for del Pezzo surfaces, I will focus on joint work with Julian Demeio and Sam Streeter where we prove weak weak approximation for del Pezzo surfaces of degree 2 with a general point.</div><div class="event_time">14:15 &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">Conférence </a></div><br /><div class="event_speaker"> Ilia Itenberg (Sorbonne University)</div><div class="event_title">Real plane sextic curves without real singular points <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We will start with a brief introduction to topology of real algebraiccurves, and then will discuss in more details the case of curves of degree 6 inthe real projective plane. We will prove that the equisingular deformation type of asimple real plane sextic curve with smooth real part is determined by its realhomological type, that is, the polarization,exceptional divisors,and real structurerecorded in the homology of the covering K3-surface (this is a joint work with AlexDegtyarev).</div><div class="event_time">15:15 &bull; Université de Genève, Conseil Général 7-9, Room 1-05</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"> Tobias  König  (Univ. Frankfurt)</div><div class="event_title">Existence of minimizers for the Bianchi-Egnell stability inequality <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Associated to Sobolev\'s inequality, the stability inequality due to Bianchi and Egnell bounds the \'Sobolev deficit\' of a function in terms of a constant $c_{BE} > 0$ times its squared $\\dot{H}^1$-distance to the manifold of Sobolev optimizers.In this talk, I will present some recent results concerning the Bianchi-Egnell inequality. Based on new strict upper bounds for the best constant $c_{BE}$, the existence of a minimizer for $c_{BE}$ can be proved by exploiting symmetry and convexity properties of the associated quotient functional. The same findings apply for the fractional Sobolev inequality of order $s \\in (0, d/2)$, provided that the space dimension $d$ is at least two.If $d =1$ on the other hand, the Bianchi-Egnell has a surprising different behavior, which I will also address in my talk.</div><div class="event_time">15:30 &bull; EPF Lausanne, MA B1 11</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Prof. Dr. Albrecht Klemm (Universität Bonn)</div><div class="event_title">Symplectic invariants on Calabi-Yau 3 folds, modularity and stability <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We discuss techniques to calculate symplectic invariants on CY 3-folds M, namely Gromov-Witten (GW) invariants, Pandharipande-Thomas (PT) invariants, and Donaldson-Thomas (DT)  invariants. Physicallythe latter are closely related to BPS brane bound states in type IIA string compactifications on M.  We focus on the rank r_6=1  DT invariants  that count D6-D2-D0 brane bound states related to PT- and  high genus GW invariants, which are calculable by mirror symmetry and topological string B-model methods modulo certain boundary conditions, and the rank zero DT invariants that count rank r_4=1 D4-D2-D0 brane bound states. It has been conjectured  by Maldacena, Strominger, Witten and  Yin that  the latter are governed by an index that has modularity properties to due S-duality in string theory and extends to a mock modularity index of higher depth for r_4>1. Again the modularity allows to fix the at least the r_4=1 index up to boundary conditions fixing their polar terms.  Using Wall crossing formulas obtained by Feyzbakhsh certain PT invariants  close to the Castelnouvo bound can be related to the r_4=1,2  D4-D2-D0 invariants. This provides further boundary conditions for topological string B-model approach as well as for the D4-D2-D0 brane indices.  The approach allows to prove the Castenouvo bound and  calculate the  r_6=1  DT- invariants or the GW invariants to higher genus than hitherto possible.</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>';