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. 1</span>      <span style="float: right; text-align:right; width: 250px;">16.9 - 20.9.2024</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Autumn Semester 2024</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, September 16      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Sam Canning (ETH Zürich)</div><div class="event_title">The tautological ring of the moduli space of stable curves is rarely Gorenstein <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A central difficulty in the study of the intersection theory of the moduli space of curves is that there may exist tautological classes that are nonzero but intersect trivially with all tautological classes of complementary codimension. I will explain some recent progress on studying such classes by intersecting with classes outside of the tautological ring.</div><div class="event_time">15:30 &bull; ETH Zentrum, Building ITS, Room  </div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, September 17      </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/s/daco-seminar">DACO Seminar</a></div><br /><div class="event_speaker"> Daniil Dmitriev (ETH Zurich)</div><div class="event_title">Robust Mixture Learning when Outliers Overwhelm Small Groups <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We study the problem of estimating the means of well-separated mixtures when an adversary may add arbitrary outliers. While strong guarantees are available when the outlier fraction is significantly smaller than the minimum mixing weight, much less is known when outliers may crowd out low-weight clusters - a setting we refer to as list-decodable mixture learning (LD-ML). In this case, adversarial outliers can simulate additional spurious mixture components. Hence, if all means of the mixture must be recovered up to a small error in the output list, the list size needs to be larger than the number of (true) components. We propose an algorithm that obtains order-optimal error guarantees for each mixture mean with a minimal list-size overhead, significantly improving upon list-decodable mean estimation, the only existing method that is applicable for LD-ML. Although improvements are observed even when the mixture is non-separated, our algorithm achieves particularly strong guarantees when the mixture is separated: it can leverage the mixture structure to partially cluster the samples before carefully iterating a base learner for list-decodable mean estimation at different scales.</div><div class="event_time">14:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"> Vladimir Dotsenko (Strasbourg)</div><div class="event_title">Stable Lie algebra homology and wheeled operads <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I shall recall the definition of a wheeled operad and explain how homotopy invariants of wheeled operads appear naturally when computing stable homology of Lie algebras of derivations of free algebras. This a common generalization of the Loday-Quillen-Tsygan theorem on additive K-theory of an associative algebra, and the Fuchs\' stability theorem for homology of the Lie algebra of vector fields. I shall also discuss the (arguably more important) case of the Lie algebras of divergence zero derivations.</div><div class="event_time">15:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"> Anshul Adve (Princeton University)</div><div class="event_title">Algebraic equations characterizing hyperbolic surface spectra <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Given a compact hyperbolic surface together with a suitable choice of orthonormal basis of Laplace eigenforms, one can consider two natural spectral invariants: 1) the Laplace spectrum Lambda, and 2) the 3-tensor C_{ijk} representing pointwise multiplication (as a densely defined map L^2 x L^2 -> L^2) in the given basis. Which pairs (Lambda,C) arise this way? Both Lambda and C are highly transcendental objects. Nevertheless, we will give a concrete and almost completely algebraic answer to this question, by writing down necessary and sufficient conditions in the form of equations satisfied by the Laplace eigenvalues and the C_{ijk}. This answer was conjectured by physicists, who introduced these equations (in an equivalent form) as a rigorous model for the crossing equations in conformal field theory.</div><div class="event_time">15:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.2 </div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"> Anton Khoroshkin (Haifa)</div><div class="event_title">On Generating Series of Cohomology of Generalized Configuration Spaces <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A generalized configuration space on X consists of a collection of points on X with a prescribed rule determining which points may not coincide. I will introduce a new algebraic structure on the union of these spaces for X=R^n, which generalizes the concept of the little discs operad. I will demonstrate how one extracts information about the Hilbert series of cohomology rings out of this algebraic structure. Surprisingly, the same method can be applied to obtain generating series for various combinatorial data associated with graphs, such as the number of Hamiltonian paths, Hamiltonian cycles, acyclic orientations, and chromatic polynomials.If time permits, I will introduce certain compactifications of these configuration spaces for X=C that generalize the Deligne-Mumford compactification of the moduli spaces of rational curves with marked points, and I will present the formulas for the generating series of their cohomology.The talk is based on the joint work with my student D.Lyskov.</div><div class="event_time">16:30 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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">Robert Nowak (Universität Ulm)</div><div class="event_title">What is... the arithmetic of curves and semistable reduction? <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let Y be an algebraic curve over a number field K of genus at least 1. The reduction behavior of Y to characteristic p&gt;0 can be used to compute arithmetic invariants of the curve. In this talk we will introduce notions of good, bad, and semistable reduction and discuss their connection to the L-series and the conductor of the curve. In the special case of hyperelliptic curves and p = 2, we will study the minimal extension over which the curve attains semistable reduction and the automorphism groups of the special fiber.</div><div class="event_time">16:30 &bull; UZH Zentrum, Building KO2, Room F 150</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.pauli-lectures.ethz.ch/">Wolfgang Pauli Lectures</a></div><br /><div class="event_title"><a class="external" href="https://pauli-lectures.ethz.ch/">Quantum Computing and the Entanglement Frontier</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The quantum laws governing atoms and other tiny objects seem to defy common sense, and information encoded in quantum systems has weird properties that baffle our feeble human minds. John Preskill will explain why he loves quantum entanglement, the elusive feature making quantum information fundamentally different from information in the macroscopic world. By exploiting quantum entanglement, quantum computers should be able to solve otherwise intractable problems, with far-reaching applications to cryptology, materials, and fundamental physical science. Preskill is less weird than a quantum computer, and easier to understand.</div><div class="event_time">17:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room F 30</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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">Dr. Christian Urech (ETHZ)</div><div class="event_title">Cubical geometry of Cremona groups <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Cremona groups are the groups of birational transformations of projective spaces. They have been the delight of algebraic geometers and group theorists in both, classical and modern times. Recently, geometric group theory and dynamics have opened up new viewpoints on the subject. In this talk, I will give a short introduction to Cremona groups and explain some natural constructions of isometric actions on negatively curved cube complexes. From those, we deduce old and new results. No prior knowledge of algebraic geometry nor geometric group theory will be assumed. This is joint work with Anne Lonjou.</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, September 18      </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/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker"> Aitor Iribar López (ETH Zürich)</div><div class="event_title">Complex abelian varieties and their moduli I <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Seminar lecture ISeminar goals: review the moduli of abelian varieties and how they degenerate, understand the construction of its toroidal compactifications, using inputs from tropical and logarithmic geometry, study different topics that arise naturally:intersection theory on these moduli spaces, the compactification interesting loci from, logarithmic abelian varieties and some arithmetic side of the whole story.See https://people.math.ethz.ch/~airibar/reading_seminar</div><div class="event_time">13:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room F 26.1</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://memento.epfl.ch/event/probability-and-stochastic-analysis-seminar/">Probability (and Stochastic Analysis) Seminar </a></div><br /><div class="event_speaker"> Xin  Sun  (Peking University)</div><div class="event_title">Backbone Exponent and Annulus Crossing Probability for 2d Percolation <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 first review the recent derivation of the backbone exponent for 2D percolation joint with Nolin, Qian, and Zhuang. The method is based on the coupling between SLE and Liouville quantum gravity (LQG), and the integrability of the Liouville conformal field theory (LCFT) that governs the LQG surfaces. The value of the backbone exponent turns out to be a transcendental number that is the root an elementary equation. Then I will present a forthcoming result joint with Zhuang that computes the exact probability that there are two disjoint paths of the same color crossing an annulus. The backbone exponent captures its leading asymptotic, while the rest of the roots in the aforementioned elementary equation captures the asymptotic of all the remaining terms. This derivation is based on the matter-Liouville-ghost decomposition of 2D quantum gravity coupled with conformal matter, which was understood in the annulus in a previous work joint with Ang and Remi. The same method also gives the probability that there is at least one path crossing the annulus, and the probability that there is at least one path of each color crossing the annulus, which were previously predicted by Cardy.</div><div class="event_time">16:00 &bull; EPF Lausanne, Bernoulli Center</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.pauli-lectures.ethz.ch/">Wolfgang Pauli Lectures</a></div><br /><div class="event_title"><a class="external" href="https://pauli-lectures.ethz.ch/lectures24.html">Learning in a Quantum World</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We live in a quantum world, yet we are classical beings, and sometimes our classical nature impedes our ability to interact with, learn from, and understand the underlying quantum reality. I\'ll describe recently developed methods for improving our ability to learn about the quantum world using both classical machines and quantum machines. With these tools, we can predict and verify properties of exotic many-particle systems, and unlock facets of nature that would otherwise be deeply concealed.</div><div class="event_time">16:45 &bull; ETH Zentrum, Building HPV, Room G 4</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Thursday, September 19      </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"> Yulieth Prieto (ICTP)</div><div class="event_title">Projective Hyperkähler Manifolds with Large Picard Number <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Compact Hyperkähler manifolds (also known as IHS) are notable Kähler manifolds renowned for their rich and intriguing geometry. In the first part of the talk, we will introduce the key definitions, properties, and examples of Hyperkähler manifolds that deform to the Hilbert scheme of n points on a K3 surface. This remarkable family will be the focus of the second part of the talk.Using classical results from quadratic forms and advanced methods from Bridgeland stability conditions, we will show that any projective Hyperkähler manifold (deforming to the Hilbert scheme of n points on a K3 surface) with a Picard number at least 4 is always isomorphic to a moduli space of (twisted) stable sheaves on a K3 surface. We will also discuss examples with Picard numbers less than 4, including cases that are not birational to a moduli space of twisted sheaves on a K3 surface. These examples reveal connections to an open problem in algebraic geometry regarding the rationality of cubic fourfolds.</div><div class="event_time">14:15 &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.pauli-lectures.ethz.ch/">Wolfgang Pauli Lectures</a></div><br /><div class="event_title"><a class="external" href="https://pauli-lectures.ethz.ch/lectures24.html">Finding Local Minima and Certifying Quantum States</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I’ll describe two recent results from our group at Caltech. (1) Finding local minima of the energy in quantum systems is quantumly easy and classically hard. (2) Single-qubit measurements suffice for efficiently certifying that a state in the lab is close to a desired target state.References: (1) Local minima in quantum systems, Chi-Fang Chen, Hsin-Yuan Huang, John Preskill, Leo Zhou, arXiv:2309.16596. (2) Certifying almost all quantum states with few single-qubit measurements, Hsin-Yuan Huang, John Preskill, Mehdi Soleimanifar, arXiv:2404.07281.</div><div class="event_time">16:45 &bull; ETH Zentrum, Building HPV, Room G 4</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Friday, September 20      </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/tggroup/doku.php?id=fables">Séminaire "Fables Géométriques" </a></div><br /><div class="event_speaker"> Nikita  Kalinin  (Guangdong Technion Israel Institute of Technology, China)</div><div class="event_title">Tropical formulaes for the number &#960; <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We will see how the same infinite series appear in 1) counting areas in between of Ford circles, 2) studying tropical caustics of convex domains 3) expansion a function in a certain Shauder basis associated with Farey fractions. Joint work with M. Shkolnikov.</div><div class="event_time">14:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"> Michael  McNulty  (Michigan State University  )</div><div class="event_title">Stable blowup for the higher-dimensional Skyrme model <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Skyrme model is a geometric field theory and a quasilinear modification of the nonlinear sigma model, i.e., wave maps into the sphere. In 3+1 dimensions, it is known that this modification prevents self-similar collapse and that global existence holds for large data. I will discuss recent work which demonstrates that this is not the case in 5+1 dimensions. In particular, Skyrme’s modification provides a stable mechanism for finite-time blowup at the self-similar rate.</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">Prof. Dr. Irene Bouw (Universität Ulm)</div><div class="event_title">Computing the Weil-Deligne representation of a curve via stable reduction <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let Y be a curve defined over a p-adic field. The local Galois representation of Y is determined by a Weil-Deligne representation. We explain how to compute this representation from the stable reduction of Y to characteristic p>0.   This is joint works with D.K. Do, R. Nowak, S. Wewers, and X. Zhang.</div><div class="event_time">14:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Johannes Schmitt (ETH Zürich)</div><div class="event_title">Enumerative invariants from log intersection numbers <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Enumerative geometry counts geometric objects satisfying a list of properties. An important method in the area is to obtain these counts as intersection numbers on a suitable moduli space Mbar. In the talk I explain how logarithmic intersection theory can be used in different examples to define intersection numbers which are independent of the precise choice of this space Mbar. After a discussion of (double) Hurwitz numbers, we\'ll also see a new class of invariants - called k-leaky double Hurwitz descendants - defined in joint work with Cavalieri and Markwig. I discuss some of their properties, show tropical formulas calculating them and present some questions on their enumerative interpretation.</div><div class="event_time">16:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.2</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>';