var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-32"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-30"><img src="//www2.math.ethz.ch/smsjs/images/arrow_right.png"/></a></div>    <div class="sms_title">      <span style="float: left;">SMS</span>      <span>SWISS MATHEMATICAL SOCIETY</span>      <span style="float: right;">SMG</span>    </div>    <div class="sms_info">      <span style="float: left; width: 250px;">Bulletin no. 13</span>      <span style="float: right; text-align:right; width: 250px;">11.12 - 15.12.2023</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Autumn Semester 2023</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, December 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://algebra.dmi.unibas.ch/seminar.html">Seminar Algebra and Geometry</a></div><br /><div class="event_speaker"> Stefan Kebebus (University of Freiburg im Breisgau)</div><div class="event_title">Title T.B.A.</div><div class="event_time">10:30 &bull; Universität Basel, Spiegelgasse 5, Seminarraum 05.001</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://theory.epfl.ch/seminar/">Theory and Combinatorics Seminar</a></div><br /><div class="event_speaker"> Peter Manohar</div><div class="event_title">Title T.B.A.</div><div class="event_time">11:00 &bull; EPF Lausanne, GA 321</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde">Bernoullis Tafelrunde</a></div><br /><div class="event_speaker"> Therese Mörschell (ETH)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde/detail/bernoullis-tafelrunde-therese-moerschell-eth/">Title T.B.A.</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>tba&lt;/p></div><div class="event_time">12:15 &bull; Universität Basel</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/talks-in-mathematical-physics">Talks in Mathematical Physics</a></div><br /><div class="event_speaker"> Francesco Bonechi (U. Florenz )</div><div class="event_title">BV pushforward of topological theories   <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />https://www.math.uzh.ch/mat074</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_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.unil.ch/dsa/en/home/menuinst/seminaires--evenements/research-seminars.html">Talks in Actuarial Mathematics </a></div><br /><div class="event_speaker"> Vitalii Makogin (University of Ulm, Germany)</div><div class="event_title">Actuarial Seminar: Vitalii Makogin (University of Ulm, Germany) <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The talk is dedicated to exploring limiting distributions for integral functionals applied to transformed (subordinated) Gaussian random fields. Moreover, we consider the general non-stationary Gaussian random fields, including stationary and anisotropic special cases. Particular attention is given to the volumes of excursion sets with results obtained through the Hermite expansion technique. Key contributions to the theory of limit theorems for random fields include: - A Gaussian limit for volumes of excursion sets of long-range dependent random fields is proved with the normalization different from CLT under the short-range dependence.- The limit theorems under long-range dependence are extended to the non-stationary Gaussian random fields. Moreover, integration domains now grow in the van Hove sense, which allows for more flexibility in their geometry.- The subordination allows getting the limit theorems for the class of random fields with infinite variance.</div><div class="event_time">14:00 &bull; EPF Lausanne, UniL campus, Extranef - 109</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.math.uzh.ch/mat760">Ergodic theory and dynamical systems seminar</a></div><br /><div class="event_speaker">Prof. Dr. Tim Austin (University of Warwick)</div><div class="event_title">A dynamical proof of the Shmerkin--Wu theorem <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let a &lt; b be multiplicatively independent integers, both at least 2. Let A,B be closed subsets of [0,1] that are forward invariant under multiplication by a, b respectively, and let C be A x B. An old conjecture of Furstenberg asserted that any line not parallel to either axis must intersect C in Hausdorff dimension at most max(dim C,1)-1. He was able to prove a partial result in this direction using a new class of measure-valued processes, now referred to as "CP chains". A few years ago, Shmerkin and Wu independently gave two different proofs of Furstenberg\'s conjecture. In this talk I will sketch a more recent third proof that builds on some of Furstenberg\'s original results. In addition to those, the main ingredients are a version of the Shannon--McMillan--Breiman theorem relative to a factor and some standard calculations with entropy and Hausdorff dimension.</div><div class="event_time">15:00 &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/fim/activities/nachdiplom-lectures">Nachdiplomvorlesung</a></div><br /><div class="event_speaker"> Javier Fresán (Sorbonne Université)</div><div class="event_title">E-functions and geometry</div><div class="event_time">16:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG , Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.math.uzh.ch/mat760">Ergodic theory and dynamical systems seminar</a></div><br /><div class="event_speaker">Prof. Dr. Konstantin Khanin (University of Toronto)</div><div class="event_title">Typical rotation numbers for families of circle maps with singularities <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I shall discuss how one can define in a natural way the notion of typical rotation numbers for families of circle maps with singularities. This problem is related to a well known fact that in the case of maps with singularities the set of parameters, corresponding to irrational rotation numbers, has zero Lebesgue measure. Our approach is based on the hyperbolicity of renormalizations. I shall also discuss a natural setting for the Kesten theorem in the case of maps with singularities.</div><div class="event_time">16:15 &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="http://www.iaa.tu-bs.de/konmerz/gausseminar/">GAuS Seminar</a></div><br /><div class="event_speaker"><a class="external" href="https://math.ethz.ch/people/gimatild"> Matilde Gianocca (ETH Z&uuml;rich, Switzerland)</a></div><div class="event_title">Morse Index Stability for Conformally Invariant Lagrangians in two dimensions <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In the first part of the talk we will give an introductory explanation of the so-called bubble-tree convergence for critical points of conformally invariant Lagrangians on Riemann Surfaces. We will then proceed to discuss Morse Index Stability along these sequences, which relies on L2,1-quantization results. The talk is based on joint work with F. Da Lio and T. Rivière.</div><div class="event_time">17:00 &bull; Online via Zoom</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, December 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" 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"> Shiyu Shen (IST Austria)</div><div class="event_title">Title T.B.A.</div><div class="event_time">10:15 &bull; EPF Lausanne</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"> Gady Kozma (Weizmann Institute & UNIGE)</div><div class="event_title">Groups with harmonic functions whose gradient goes to zero <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We will discuss the question: which finitely generated groups support aharmonic function with a gradient going to zero? This problem is inspired by a conjecture of Gromov and Cheeger about the reduced l_p cohomology and is also of interest from the point of view of \'weak hyperbolicity\'. We will discuss constructions of amenable, and even Liouville, groups with this property. All notions will be defined in the talk. Joint work with Gidi Amir, Guy Blachar and Maria Gerasimova.</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_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. Guy Casale (Université Rennes 1)</div><div class="event_title">A differential approach to Ax-Schanuel theorems <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Ax-Schanuel theorems are statements about the Zariski closure of a formal (non-constant) curve lying on a leaf of a foliation of a complex algebraic variety. Here are two instances of this family of theorems:&lt;BR> Theorem (Ax): For $t in (C[[s]]-C)^n$, if $trdeg C(t_1,..., t_n, exp(t_1),..., exp(t_n))/C &lt; 1+n$ then a $Z$-linear combination of $t_i$\'s is constant. &lt;BR> Theorem (Pila-Tsimerman): For $t in (C[[s]]-C)^n$, if $trdeg C(t_1,...,t_n, j(t_1),..., j(t_n), ..., j\'\'(t_n))/C &lt; 1+3n$ then there exist $k\\leq l-1$ and $h$ in $PGL_2^+(Q)$ such that $t_k = h(t_l)$.&lt;BR> The natural extension of these theorems to developing maps of a rational $(G, G/H)$-structure on a algebraic variety splits in two different parts: 1/ prove that $j(t_k)$ is algebraic over $C(j(t_l))$; 2/ prove the existence of $h$. I will explain how the first part can be obtained from a general result on principal connexions using elementary differential Galois theory and how the second part is obtained in the special case of product of projective structures on curves using model theory of differentially closed fields.</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_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"> Laurence Halpern (Université de Sorbonne Paris Nord)</div><div class="event_title">Modal analysis of the Robin-Schwarz operator <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Robin-Schwarz operator describes one iteration of the Schwarz domain decomposition algorithm with Robin transmission conditions. Little is known on the spectral properties of this operator which is neither self-adjoint nor compact. We give here for the first time a method to compute the eigenmodes with separation of variables, and prove that they are a complete family. These eigenmodes are of paramount importance for the design and understanding of multi-level domain decomposition methods. The problem inherently couples oscillatory and exponential series, but no result in approximation or spectral theory existing so far can be applied. The analysis calls for multiple tools: regularity results, complex analysis, including non harmonic Fourier series and almost periodic functions. We focus on the special case of 2 by 2 subdomains, but we have little doubts that it opens the door for more general geometries.</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_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"> Valentin Bosshard (ETH Zürich)</div><div class="event_title"> Lagrangian cobordisms and the Lagrangian cobordism group of Weinstein manifolds  <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />An A-infinity category can be studied by finding exact triangles. In the case of the Fukaya category of a symplectic manifold, there is a geometric way to get exact triangles: by Lagrangian cobordisms. But how many exact triangles can be recovered by Lagrangian cobordisms? One way to measure this is by comparing the Lagrangian cobordism group to the Grothendieck group of the Fukaya category. In this talk, we discuss the setting of exact conical Lagrangian submanifolds in Liouville manifolds and compute Lagrangian cobordism groups of Weinstein manifolds. As an application, we get a geometric interpretation for Viterbo restriction for Lagrangian cobordism groups.</div><div class="event_time">15:00 &bull; Université de Neuchâtel, Rue Emile-Argand 11, Room B217</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/analysis-seminar">Analysis Seminar</a></div><br /><div class="event_speaker"> Lorenzo  Sarnataro (Princeton University)</div><div class="event_title">Optimal regularity for minimizers of the prescribed mean curvature functional over isotopies  <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 describe the regularity theory for surfaces minimizing the prescribed mean curvature functional over isotopies in a closed Riemannian 3-manifold, which is a prescribed mean curvature counterpart of the celebrated regularity result of Meeks, Simon and Yau about minimizers of the area functional over isotopies. Whereas for the area functional minimizers over isotopies are smooth embedded minimal surfaces, minimizers of the prescribed mean curvature functional turn out to be C^{1,1} immersions which can have a large self-touching set where the mean curvature vanishes. Even though the proof broadly follows the same general strategy as in the case of the area functional, several new ideas are needed to deal with the lower regularity setting. This regularity theory plays an important role in Z. Wang-X. Zhou’s recent proof of the existence of 4 embedded minimal spheres in a generic metric on the 3-sphere. The results in this talk are joint work with Douglas Stryker (Princeton).</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_fr"><a class="external" href="https://www.unifr.ch">Université de Fribourg</a></div><div class="event_type"><a class="external" href="https://www.unifr.ch/math/de/info/kolloquium.html">Colloquium </a></div><br /><div class="event_speaker"> Amir Dzambic (Christian-Albrechts-Universität zu Kiel)</div><div class="event_title">Numbers as sums of (four) squares <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Representing numbers as sums of squares or more generally as values of integral quadratic forms is certainly a question that belongs to the very classics of mathematics and that had a very deep impact on the development of many important theories of modern algebra and number theory. The goal of my talk will be to substantiate the above thesis by recalling A. Hurwitz’s theory of integral quaternions, which he used to develop  a new proof of Jacobi’s four squares theorem. In my talk I will give an overview of Hurwitz’s theoryand present a variant of Hurwitz’s proof using the Zeta function of the ring of Hurwitz’s quaternions.</div><div class="event_time">17:15 &bull; Université de Fribourg, room Phys 2.52</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, December 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"> Amir Dzambic (Christian-Albrechts-Universität zu Kiel)</div><div class="event_title">Lattices of minimal co-volume in some Lie groups of higher rank <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The question of identifying the lattices (i.e. discrete subgroups of finiteco-volume) of minimal co-volume in Lie groups has a long history start-ing with the work of C.-L. Siegel who showed that the (2,3,7)-trianglegroup is the unique lattice (up to conjugation) of minimal co-volume inthe special linear group PSL2(R). By a recent result of F. Thilmanya similar uniqueness result holds for the group PSLn(R) with n > 2,where the minimal co-volume lattice is (a conjugate of) PSLn(Z). Sim-ilar, partly weaker, results are known for other (simple) Lie groups bythe work of many mathematicians such as Gehring-Martin, Belolipetsky,Belolipetski- Emery, Emery-Stover, Emery-Kim.In my talk I would like to report on the joint project with K. Holmand R. Köhl on minimal co-volume lattices in the (split) symplecticgroup. If the time permits I will also briefly discuss a related ques-tion on minimal co-volume irreducible lattices in non-simple Lie groupssuch as PSL2(R)n.</div><div class="event_time">10:20 &bull; Université de Fribourg, 0.05 PER23</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"> Pim Spelier (Leiden University)</div><div class="event_title">Log gluing log curves and log cohomological field theories <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The gluing maps on the moduli spaces Mbar_{g,n} have played a crucial role in the intersection theory of Mbar_{g,n}, for example playing a key part in the definition of its tautological ring and of cohomological field theories. In the last few years, interpreting Mbar_{g,n} as a logarithmic space has also been an incredibly useful tool for understanding classical invariants, such as the double ramification (DR) cycle. However, joining these two concepts has been proven difficult, as the gluing maps are not logarithmic and hence the log structure and the gluing do not interact. In this talk I will explain the DR cycle, explain the difficulty in log gluing, and present a definition of log gluing. This also allows for the definition of log cohomological field theories, and in particular we find that the log DR cycle is a log cohomological field theory.This talk is based on joint work with David Holmes (arxiv:2308.01099). No previous knowledge of DR cycles or log geometry is assumed.</div><div class="event_time">13:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/analysis/analysis-seminar">Analysis Seminar</a></div><br /><div class="event_speaker"> Theodore Drivas (Stony Brook University)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-analysis-and-mathematical-physics-theodore-drivas-stony-brook-university/">Permanent features of 2d fluids</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>We will discuss aspects of the global picture of 2D fluids. Steady states, deterioration of regularity for time dependent solutions as well as for the Lagrangian flowmap, as well as conjectural pictures about the weak-* attractor and generic behavior by Shnirelman and Sverak. &lt;/p>&lt;p>&lt;strong>Notice the special time!&lt;/strong>&lt;/p></div><div class="event_time">15:15 &bull; Universität Basel, Online via Zoom</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"> Pedro Boavida de Brito (Instituto Superior Técnico, University of Lisbon)</div><div class="event_title">Torus tricks and configuration spaces <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Given a topological embedding (i.e. injective continuous map), evaluation on finite subsets defines a map between configuration spaces which is coherent as we vary cardinalities. It turns out that, if the codimension is at least three, no homotopically information is lost in this process. This is in stark contrast to the situation in codimension zero, as shown by Krannich-Kupers. I will discuss some constructions and ideas involved in showing the high-codimension result, notably, a configuration space version of a torus trick from classical geometric topology. This is joint work with Michael Weiss.</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_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"> Julia Wolf (University of Cambridge)</div><div class="event_title"><a class="external" href="https://forms.gle/C1hzHfSHWnYDRakM9">When is a Mathematical Object Well-Behaved?</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk we will come at this question from two different angles: first, from the viewpoint of model theory, a subject in which for nearly half a century the notion of stability has played a central role in describing tame behaviour; secondly, from the perspective of combinatorics, where so-called regularity decompositions have enjoyed a similar level of prominence in a range of finitary settings, with remarkable applications.In recent years, these two fundamental notions have been shown to interact in interesting ways. In particular, it has been shown that mathematical objects that are stable in the model-theoretic sense admit particularly well-behaved regularity decompositions. In this talk we will explore this fruitful interplay in the context of both finite graphs and subsets of abelian groups.To the extent that time permits, I will go on to describe recent joint work with Caroline Terry (The Ohio State University), in which we develop a higher-arity generalisation of stability that implies (and in some cases characterises) the existence of particularly pleasant higher-order regularity decompositions.Registration requested: https://forms.gle/C1hzHfSHWnYDRakM9</div><div class="event_time">16:15 &bull; EPF Lausanne, Bernoulli Center</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/sam/news-and-events/zhacm-colloquia">Zurich Colloquium in Applied and Computational Mathematics</a></div><br /><div class="event_speaker">Dr. Dmitry Batenkov (Tel Aviv University)</div><div class="event_title">Super-resolution of sparse measures: recent advances <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The inverse problem of computational super-resolution is to recover fine features of a signal from bandlimited and noisy data. Despite long history of the question and its fundamental importance in science and engineering, relatively little is known regarding optimal accuracy of reconstructing the high resolution signal components, and how to attain it with tractable algorithms.In this talk I will describe recent progress on deriving optimal methods for super-resolving sparse sums of Dirac masses, a popular model in numerous applications such as spectral estimation, direction of arrival, imaging of point sources, and sampling signals below the Nyquist rate. Time permitting, I will also discuss generalizations of the theory and algorithms in several directions.</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://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"> Daniela Portillo del Valle (Universität Zürich, Switzerland)</div><div class="event_title">Working group step-reinforced random walks: On the distribution of the limiting velocity</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, December 14      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://calendar.google.com/calendar/embed?mode=AGENDA&height=600&wkst=2&bgcolor=%23FFFFFF&src=t36it03v52cus2detrvinlgk18%40group.calendar.google.com&color=%235F6B02&ctz=Europe%2FZurich">Groups, Arithmetic and Algebraic Geometry Seminar </a></div><br /><div class="event_speaker"> Gergely Bérczi (Aarhus University)</div><div class="event_title">The geometry of Hilbert scheme of points on manifolds <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />While the Hilbert scheme of points on surfaces is extensively studied, the Hilbert scheme of points on higher-dimensional manifolds proves to be notoriously complex, exhibiting wild and pathological properties. Our understanding of their topology and geometry is very limited.In this survey I will present recent developments in various aspects of their geometry. I will discuss the distribution of torus fixed points within the components of the Hilbert scheme (work with J. Svendsen), a new formula for tautological integrals over geometric components (work with A. Szenes),  and p-adic integration on Hilbert schemes leading to new invariants of hypersurface singularities (work with I. Rossinelli).</div><div class="event_time">13:15 &bull; EPF Lausanne</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://stat.ethz.ch/events/research_seminar">Research Seminar in Statistics</a></div><br /><div class="event_speaker"> Shuheng Zhou (University of California)</div><div class="event_title">Concentration of measure bounds for matrix-variate data with missing values <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We consider the following data perturbation model, where the covariates incur multiplicative errors. For two random matrices U, X, we denote by (U \\circ X) the Hadamard or Schur product, which is defined as (U \\circ X)_{i,j} = (U_{i,j}) (X_{ij}). In this paper, we study the subgaussian matrix variate model, where we observe the matrix variate data through a random mask U: \\mathcal{X} = U \\circ X, where X = B^{1/2} Z A^{1/2}, where Z is a random matrix with independent subgaussian entries, and U is a mask matrix with either zero or positive entries, where $E[U_{ij}] \\in [0,1]$ and all entries are mutually independent.Under the assumption of independence between X and U, we introduce componentwise unbiased estimators for estimating covariance A and B, and prove the concentration of measure bounds in the sense of guaranteeing the restricted eigenvalue(RE) conditions to hold on the unbiased estimator for B, when columns of data matrix are sampled with different rates. We further develop multiple regression methods for estimating the inverse of B and show statistical rate of convergence. Our results provide insight for sparse recovery for relationships among entities (samples, locations, items) when features (variables, time points, user ratings) are present in the observed data matrix X with heterogeneous rates. Our proof techniques can certainly be extended to other scenarios. We provide simulation evidence illuminating the theoretical predictions.</div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/talks-in-financial-and-insurance-mathematics">Talks in Financial and Insurance Mathematics</a></div><br /><div class="event_speaker"><a class="external" href="https://people.epfl.ch/urban.ulrych">Dr. Urban Ulrych (EPFL Lausanne)</a></div><div class="event_title">Dynamic Currency Hedging with Non-Gaussianity and Ambiguity <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This paper introduces a non-Gaussian dynamic currency hedging strategy for globally diversified investors with ambiguity. It provides theoretical and empirical evidence that, under the stylized fact of non-Gaussianity of financial returns and for a given optimal portfolio, the investor-specific ambiguity can be estimated from historical asset returns without the need for additional exogenous information. Acknowledging non-Gaussianity, we compute an optimal ambiguity-adjusted mean-variance (dynamic) currency allocation. Next, we propose an extended filtered historical simulation that combines Monte Carlo simulation based on volatility clustering patterns with the semi-parametric non-normal return distribution from historical data. This simulation allows us to incorporate investor\'s ambiguity into a dynamic currency hedging strategy algorithm that can numerically optimize an arbitrary risk measure, such as the expected shortfall. The out-of-sample backtest demonstrates that, for globally diversified investors, the derived non-Gaussian dynamic currency hedging strategy is stable, robust, and highly risk reductive. It outperforms the benchmarks of constant hedging as well as static/dynamic hedging approaches with Gaussianity in terms of lower maximum drawdown and higher Sharpe and Sortino ratios, net of transaction costs.</div><div class="event_time">17:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Friday, December 15      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/seminar-in-numerical-analysis">Seminar in Numerical Analysis</a></div><br /><div class="event_speaker"> Caroline Geiersbach (WIAS Berlin)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-in-numerical-analysis-caroline-geiersbach-wias-berlin/">Stochastic approximation for shape optimization under uncertainty</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>Many problems in shape optimization involve constraints in the form of one or more partial differential equations. In practice, the material properties of the underlying shape on which a PDE is defined are not known exactly; it is natural to use a probability distribution based on empirical measurements and incorporate this information when designing an optimal shape. Additionally, one might wish to obtain a shape that is robust in its response to certain external inputs, such as forces. It is helpful to view shape optimization problems subject to uncertainty through the lens of stochastic optimization, where a wealth of theory and algorithms already exist for finite-dimensional problems. The focus will be on the algorithmic handling of these problems in the case of a high stochastic dimension. Stochastic approximation, which dynamically samples from the stochastic space over the course of iterations, is favored in this case, and we show how these methods can be applied to shape optimization. We study the classical stochastic gradient method, which was introduced in 1951 by Robbins and Monro and is widely used in machine learning. In particular, we investigate its application to infinite-dimensional shape manifolds. Further, we present numerical examples showing the performance of the method, also in combination with the augmented Lagrangian method for problems with geometric constraints. &lt;/p>&lt;p>Joint work with: Kathrin Welker, Estefania Loayza-Romero, Tim Suchan&lt;/p>&lt;p> &lt;/p>&lt;p>For further information about the seminar, please visit this <a href="https://dmi.unibas.ch/de/forschung/mathematik/seminar-in-numerical-analysis/" title="Opens internal link in current window">webpage</a>.&lt;/p></div><div class="event_time">11:00 &bull; Universität Basel</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.unil.ch/dsa/en/home/menuinst/seminaires--evenements/research-seminars.html">Talks in Actuarial Mathematics </a></div><br /><div class="event_speaker"> Evgeni Spodarev (University of Ulm, Germany)</div><div class="event_title">Prediction of heavy–tailed random functions via excursion sets <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We use the concept of excursions for the prediction of random variables without any moment existence assumptions. To do so, an excursion metric on the space of random variables is defined which appears to be a kind of a weighted L_1 distance. Using equivalent forms of this metric and the specific choice of excursion levels, we formulate the prediction problem as a minimization of a certain target functional which involves the excursion metric. Existence of the solution and weak consistency of the predictor are discussed. An application to the extrapolation of stationary heavy-tailed random functions illustrates the use of the aforementioned theory. Numerical experiments with the prediction of Gaussian, alpha- and  max-stable  random functions show the practical merits of the approach.Joint work with A. Das and V. Makogin</div><div class="event_time">11:00 &bull; EPF Lausanne, UniL campus, Extranef - 109</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"> Lars Eric Hientzsch</div><div class="event_title">On the ill-posedness of the 2D Boussinesq equations in the class of bounded initial data <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Boussinesq equations describe the evolution of a stratified fluid under the influence of gravity. We investigate the system in vorticity form and with a stable continuous background stratification increasing with depth (spectrally stable density profile).We prove that the system is strongly ill-posed in the class of data with bounded initial vorticity and density gradient.The mechanism that allows us to exhibit the norm-inflation in infinitesimal time is purely nonlinear - in contrast to previous results on mild ill-posedness of the system.Time permitting, applications to the 3D axisymmetric Euler equations with small bounded initial vorticity are discussed.Based on joint work with R. Bianchini (IAC Rome) and F. Iandoli (Università della Calabria).</div><div class="event_time">14:15 &bull; EPF Lausanne</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://stat.ethz.ch/events/zukost">ZüKoSt Zürcher Kolloquium über Statistik</a></div><br /><div class="event_speaker"> Sylvain Robert (Google)</div><div class="event_title">Dealing with contamination in geo-experiments <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Advertisers are interested in measuring the effectiveness of their online marketing campaigns on various platforms. While user-based experiments are efficient and well-understood, they are not always feasible because of technical and legal reasons. Geo-based experiments are an attractive and privacy-centric alternative, where experimental units are defined as geographical regions instead of individual users. One issue with this type of experiments, however, is the presence of contamination (or interference) between units, due to natural movement of people and imprecision in geo-localization. In this work we will try to quantify the amount of contamination in our experiments and propose possible solutions to mitigate its adverse effect, both during the estimation at the end of the expriment and upstream at the design phase.</div><div class="event_time">15:15 &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://www.epfl.ch/schools/sb/research/math/statistics-seminars/">Statistics Seminar </a></div><br /><div class="event_speaker"> Anne van Delft (Columbia University)</div><div class="event_title">A statistical framework for analyzing shape in a time series of random geometric objects <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We introduce a new  framework to analyze shape descriptors that capture the geometric features of an ensemble of point clouds. At the core of our approach is the point of view that the data arises as sampled recordings from a metric space-valued stochastic process, possibly of nonstationary nature, thereby integrating geometric data analysis into the realm of functional time series analysis. We focus on the descriptors coming from topological data analysis. Our framework allows for natural incorporation of spatial-temporal dynamics, heterogeneous sampling, and the study of convergence rates. Further, we  derive  complete invariants for classes of metric space-valued stochastic processes in the spirit of Gromov, and relate these invariants to so-called ball volume processes.Under mild dependence conditions, a weak invariance principle in $D([0,1]\\times [0,\\mathscr{R}])$ is established for sequential empirical versions of the latter, assuming the probabilistic structure possibly  changes over time. Finally, we use this result to introduce novel test statistics for topological change, which are distribution free in the limit under the hypothesis of stationarity.https://arxiv.org/pdf/2304.01984.pdf (joint work with Andrew J. Blumberg)</div><div class="event_time">15:15 &bull; EPF Lausanne, MA A3 31</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. Dan Petersen (University of Stockholm)</div><div class="event_title">Top weight cohomology of M_g and the handlebody group <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Chan-Galatius-Payne have recently identified an enormous amount of nontrivial unstable cohomology classes on the moduli spaces of curves, via an identification of the "top weight" cohomology of the mapping class group with the cohomology of Kontsevich\'s graph complex. I will explain that all these classes restrict nontrivially to the handlebody subgroup of the mapping class group, i.e. those mapping classes which extend to a handlebody filling. In the process we obtain a geometrically meaningful classifying space for the handlebody group. (Joint with Louis Hainaut.)</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>';