var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-76"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-74"><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. 9</span>      <span style="float: right; text-align:right; width: 250px;">13.11 - 17.11.2023</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, November 13      </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"> Marco Inversi (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-marco-inversi-university-of-basel/">Energy conservation for fluid flows in an Onsager critical class</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/_HS23/Marco_Inversi.pdf" target="_blank">abstract</a>&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_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"> Francesca Carocci (Genève)</div><div class="event_title">What can we do with the Logarithmic Hilbert Scheme? <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In 2020 Maulik-Ranganathan defined the Logarithmic Hilbert-Scheme, which is interesting for the enumerative geometry of 3-folds;  for example, it gives access to degeneration techniques in sheaf-theoretic approaches to curve counting.  If we go one step back and look at degree d curves in toric surfaces,  the construction of the log Hilbert scheme has as a main ingredient the secondary fan of a toric fan, though as  moduli space of tropical plane curves up to translation.I will try to explain some of the ideas of the construction, trying to put emphasis on the tropical aspects of the theory.The main goal of the talk would be to understand if this theory gives rise to some interesting questions and the relation of such questions with tropical geometry. </div><div class="event_time">15:00 &bull; Université de Genève, salle 06-13</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. Denis Nesterov (IST Austria)</div><div class="event_title">Unramified Gromov-Witten and Gopakumar-Vafa invariants I  <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Kim, Kresch and Oh constructed compactified moduli spaces ofunramified maps from nodal curves to an arbitrary smooth projectivetarget. The associated invariants were called unramified Gromov-Witten invariants. In dimension 1, these spaces are familiar moduli spaces of admissible covers introduced by Harris and Mumford. In dimension 3,Pandharipande conjectured that unramified Gromov-Witten invariants areequal to Gopakumar-Vafa invariants (BPS invariants) for Fano andprimitive Calabi-Yau classes. After an introduction to unramifiedGromov-Witten theory, I will present a work in progress which aims to prove this conjecture. The approach is based on a certain wall-crossing technique, whose wall-crossing invariants are given by Hodge integrals on moduli spaces of stable marked curves.</div><div class="event_time">15:00 &bull; ETH Zentrum, Building ITS, Room  </div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/symplectic-geometry-seminar">Symplectic Geometry Seminar</a></div><br /><div class="event_speaker"> Ipsita Datta (ETH)</div><div class="event_title">Lagrangian cobordisms, enriched knot diagrams, and algebraic invariants <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We introduce new invariants to the existence of Lagrangiancobordisms in R^4. These are obtained by studying holomorphic diskswith corners on Lagrangian tangles, which are Lagrangian cobordismswith flat, immersed boundaries.We develop appropriate sign conventions and results to characterizeboundary points of 1-dimensional moduli spaces with boundaries onLagrangian tangles. We use these to define algebraic structures on a related "linear" case of Lagrangian cobordisms in surface times complex plane.This talk is based on my thesis work under the supervision of Y.Eliashberg and on work in progress joint with J. Sabloff.</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/symplectic-geometry-seminar">Symplectic Geometry Seminar</a></div><br /><div class="event_speaker"> Yusuke Kawamoto (ETH)</div><div class="event_title">Spectral invariants over the integers <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Spectral invariants are quantitative measurements in symplectic topologycoming from Floer homology theory. We study their dependence on the choiceof coefficients in the context of Hamiltonian Floer homology. We discoverphenomena in this setting which hold for $\\Z$-coefficients and fail for allfield coefficients. We apply this to answer a symplectic version of aquestion of Hingston.</div><div class="event_time">16:25 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_be"><a class="external" href="https://www.unibe.ch">Universität Bern</a></div><div class="event_type"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Mathematisches Kolloquium </a></div><br /><div class="event_speaker">Prof. Dr. Joaquim Serra (ETH)</div><div class="event_title"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Nonlocal minimal surfaces: an invitation for the skeptics (and the convinced)</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Many physical phenomena feature interfaces that minimize their surface area, much like the effects of surface tension. Within this framework, minimal surfaces and the Ginzburg-Landau model of phase transitions, while widely applied in various research fields, are predominantly practical phenomenological models. This prompts an exploration into alternative mathematical frameworks exhibiting similar macroscopic features. Emerging initially from this mindset, nonlocal minimal surfaces have later proven to be rich and profound geometric entities. We\'ve recently discovered that these surfaces exhibit enhanced regularity compared to classical minimal surfaces. These better regularity properties position them as prime candidates for the application of variational methods. I\'ll discuss these insights in an accessible manner, highlighting their intriguing implications in the realms of minimal surfaces and phase transitions.</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, November 14      </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"> Florian Richter (EPFL)</div><div class="event_title">Multiplicative Number Theory from a dynamical perspective <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Multiplicative number theory is the study of prime numbers, factorizations, divisors, and other basic mathematical concepts related to the multiplicative structure of the integers. The focus of this lecture lies on some of the newly emerging interfaces between multiplicative number theory and ergodic theory, which has led to significant advancements in recent years. We will provide an overview of the latest developments and explore some of the new methods and applications that have emerged.</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.unil.ch/dsa/en/home/menuinst/seminaires--evenements/research-seminars.html">Talks in Actuarial Mathematics </a></div><br /><div class="event_speaker"> Hanspeter Schmidli (University of Cologne, Germany)</div><div class="event_title">Stabilizing the surplus process through the control of Drawdowns <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The drawdown is the loss of the surplus process compared its historical maximum. In order to stabilize the surplus one tries to keep the surplus close the its maximum; that is, keeping the drawdown small. We use proportional reinsurance to control the drawdown and measure the time the drawdown spends below a predefined barrier. If the time in drawdown is the only criterion, the maximum will never increase under the optimal strategy, see Brinker and Schmidli (2022). To avoid this, we maximise simultaneously the increase of the maximum. Dependent on how we weight the two contradicting criteria, we obtain different strategies, of which some are surprising. The talk is based on joint work with Leonie Brinker.</div><div class="event_time">11:00 &bull; EPF Lausanne, UniL campus, Extranef - 110</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. Evgeny Shinder (University of Sheffield)</div><div class="event_title">Motivic invariants of birational maps <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will speak about invariants of birational maps taking values in the Grothendieck ring of varieties, and about applications of these invariants to the properties of birational maps and to the structure of the Grothendieck ring. This is joint work with Hsueh-Yung Lin.</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"> Dominic Phillips (University of Edinburgh)</div><div class="event_title">Numerics with Coordinate Transforms for Efficient Brownian Dynamics Simulations  <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Many stochastic processes in the physical and biological sciences can be modelled using Brownian dynamics with multiplicative noise. However, numerical integrators for these processes can lose accuracy or even fail to converge when the diffusion term is configuration-dependent. One remedy is to construct a transform to a constant-diffusion process and sample the transformed process instead. In this work, we explain how coordinate-based and time-rescaling-based transforms can be used either individually or in combination to map a general class of variable-diffusion Brownian motion processes into constant-diffusion ones. The transforms are invertible, thus allowing recovery of the original dynamics. We motivate our methodology using examples in one dimension before then considering multivariate diffusion processes. We illustrate the benefits of the transforms through numerical simulations, demonstrating how the right combination of integrator and transform can improve computational efficiency and the order of convergence to the invariant distribution. Notably, the transforms that we derive are applicable to a class of multibody, anisotropic Stokes-Einstein diffusion that has applications in biophysical modelling.</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_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"> Freya Behrens (EPFL)</div><div class="event_title">The statistical mechanics of synchronous local processes on graphs <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The friendly partition problem involves determining whether a given graph allows for a partition of its nodes into two nonempty sets, where each node has at least as many neighbors in its own set as in the other. Notably, not all graphs permit such a friendly partition, and even fewer accommodate a partition where a node requires an additional margin of neighbors in its own set compared to the other. We investigate the existence of such partitions and the algorithmic feasibility of finding them.A natural question is: how does a graph evolve when nodes directly adapt their states to meet these local constraints? When this adaptation occurs synchronously, it models scenarios like majority voting or cellular automata. However, it is not a given that a graph, where each node greedily iteratively applies the local rule, converges to a global solution. Our analysis examines the different types of attractors that emerge in locally constrained problems and the role of initialisation in shaping the outcome.Our tool to answer these questions is the cavity method and the backtracking dynamical cavity method from statistical physics for synchronous update processes on regular graphs. They provide the sharp transitions on the existence of solutions, as well as the dynamical phase transitions of local processes in the large system limit.</div><div class="event_time">14:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/labs/anmath/seminars/">Seminar of Analysis </a></div><br /><div class="event_speaker"> Anna Skorobogatova (University of Princeton)</div><div class="event_title">Higher codimension area-minimizers: structure of singularities and uniqueness of tangent cones <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The problem of determining the size and structure of the interior singular set of area-minimizing surfaces has been studied thoroughly in a number of different frameworks, with many ground-breaking contributions. In the framework of integral currents, when the codimension of the surface is higher than 1, the presence of singular points with flat tangent cones creates an obstruction to easily understanding the interior singularities. Little progress has been made in full generality since Almgren’s celebrated (m-2)-Hausdorff dimension bound on the singular set for an m-dimensional area-minimizing current, which was since revisited and simplified by De Lellis and Spadaro. In this talk I will discuss recent joint works with Camillo De Lellis and Paul Minter, where we establish (m-2)-rectifiability of the interior singular set of an m-dimensional area-minimizing integral current and show that the tangent cone is unique at \\mathcal{H}^{m-2}-a.e. interior point.</div><div class="event_time">14:15 &bull; EPF Lausanne, MA B2 485</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"> Ben Pineau (UC Berkeley)</div><div class="event_title">Sharp Hadamard well-posedness for the incompressible free boundary Euler equations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will talk about a recent preprint in which we establish an optimal local well-posedness theory in $H^s$ based Sobolev spaces for the free boundary incompressible Euler equations on a connected fluid domain. Some components of this result include: (i) Local well-posedness in the Hadamard sense, i.e., local existence, uniqueness, and the first proof of continuous dependence on the data, all in low regularity Sobolev spaces; (ii) Enhanced uniqueness: A uniqueness result which holds at the level of the Lipschitz norm of the velocity and the $C^{1,\\frac{1}{2}}$ regularity of the free surface; (iii) Stability bounds: We construct a nonlinear functional which measures, in a suitable sense, the distance between two solutions (even when defined on different domains) and we show that this distance is propagated by the flow; (iv) Energy estimates: We prove essentially scale invariant energy estimates for solutions, relying on a newly constructed family of refined elliptic estimates; (v) Continuation criterion: We give the first proof of a continuation criterion at the same scale as the classical Beale-Kato-Majda criterion for the Euler equations on the whole space. Roughly speaking, we show that solutions can be continued as long as the velocity is in $L_T^1W^{1,\\infty}$ and the free surface is in $L_T^1C^{1,\\frac{1}{2}}$; (vi) A novel proof of the construction of regular solutions.\\\\Our entire approach is in the Eulerian framework and can be adapted to work in relatively general fluid domains. This is based on joint work with Mihaela Ifrim, Daniel Tataru and Mitchell Taylor.</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/seminaires/lie-sem/">Lie groups and moduli spaces </a></div><br /><div class="event_speaker"> Ivo Sachs (Munich)</div><div class="event_title">Strings from graded superalgebras <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The world sheet approach to string theory, through its BRST quantization,  gives rise to a graded superalgebra. Conversely, for a given choice of a superalgebra, one may construct a theory of background fields, using a graded  Chevalley-Eilenberg construction. I will describe some solutions corresponding to different choices of the graded algebra. </div><div class="event_time">15:30 &bull; Université de Genève, Section de mathématiques, 7-9 rue du Conseil-Général, Room 1-07</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ne"><a class="external" href="https://unine.ch">Université de Neuchâtel</a></div><div class="event_type"><a class="external" href="http://www.unine.ch/math/home/colloques_et_seminaires/les-colloques-du-mardi.html">Colloque du Mardi </a></div><br /><div class="event_speaker"> Isabelle Chalendar (Université Gustave Eiffel, Champs-sur-Marne)</div><div class="event_title">Composition operators on model spaces. <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A bounded holomorphic function on the unit disk $\\D$ is inner if its boundary values are almost everywhere of modulus 1. Motivated by the study of composition operators on model spaces launched by Mashreghi and  Shabankha  we consider the following problem: for a given inner function $\\phi\\not\\in\\mathsf{Aut}(\\D)$, find a non-constant inner function $\\Psi$ satisfying the functional equation $\\Psi\\circ\\phi=\\tau\\Psi$, where $\\tau$ is a unimodular constant. We prove that this problem has a solution if and only  if $\\phi$ is of positive hyperbolic step. Joint work with  P. GUMENYUK, and J.E. McCARTHY. </div><div class="event_time">17:00 &bull; Université de Neuchâtel, Institut de Mathématiques, B103</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/news-and-events/events/lecture-series/heinz-hopf-prize-and-lectures.html">Heinz Hopf Prize / Award ceremony and lecture</a></div><br /><div class="event_speaker"> Lai-Sang Young (New York University)</div><div class="event_title">Heinz Hopf lecture I:  What happens when oscillators are disturbed?</div><div class="event_time">17:15 &bull; UZH Zentrum, Building RAA, Room G 01</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, November 15      </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/news-and-events/events/lecture-series/heinz-hopf-prize-and-lectures.html">Heinz Hopf Symposium</a></div><br /><div class="event_speaker"> Carlangelo Liverani (Università degli Studi di Roma “Tor Vergata”)</div><div class="event_title">Heat equation from a deterministic dynamics</div><div class="event_time">10:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/news-and-events/events/lecture-series/heinz-hopf-prize-and-lectures.html">Heinz Hopf Symposium</a></div><br /><div class="event_speaker"> Alex Blumenthal (Georgia Institute of Technology)</div><div class="event_title">Tractability of chaotic dynamics of noisy systems</div><div class="event_time">11:30 &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/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Denis Nesterov (IST Austria)</div><div class="event_title">Unramified Gromov-Witten and Gopakumar-Vafa invariants II  <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Kim, Kresch and Oh constructed compactified moduli spaces ofunramified maps from nodal curvesto an arbitrary smooth projectivetarget. The associated invariantswere called unramified Gromov-Witten invariants. In dimension 1,these spaces are familiar modulispaces of admissible coversintroduced by Harris and Mumford.In dimension 3, Pandharipandeconjectured that unramified GromovWitten invariants are equal toGopakumar-Vafa invariants (BPSinvariants) for Fano andprimitive Calabi-Yau classes. Afteran introduction to unramifiedGromov-Witten theory, I willpresent a work in progress whichaims to prove this conjecture. The approach is based on a certain wall-crossing technique, whose wall-crossing invariants are given by Hodge integrals on moduli spaces of stable marked curves.</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://math.ethz.ch/news-and-events/events/lecture-series/heinz-hopf-prize-and-lectures.html">Heinz Hopf Symposium</a></div><br /><div class="event_speaker"> Sylvain Crovisier (Université Paris-Saclay)</div><div class="event_title">Strong positive recurrence of smooth surface diffeomorphisms</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_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"> Marc Nualart (Imperial College London)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-analysis-and-mathematical-physics-marc-nualart-imperial-college-london/">Linear Inviscid Damping in the 2D Euler-Boussinesq system in the periodic channel</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>In this talk we consider the long-time behavior of solutions to the two dimensional non-homogeneous Euler equations under the Boussinesq approximation posed on a periodic channel. We prove inviscid damping  for the linearized equations around the stably stratified Couette flow using stationary-phase methods of oscillatory integrals. We discuss how these oscillatory integrals arise,  what are the main regularity requirements to carry out the stationary-phase arguments, and how to achieve such regularities.&lt;/p></div><div class="event_time">14:15 &bull; Universität Basel, Spiegelgasse 5, Seminarraum 05.002</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://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">Dr. Guido Maria Lido (Tor Vergata University Rom)</div><div class="event_title">Isogeny Graphs with Level Structure and Their Spectrum <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A familiar object in isogeny based cryptography is the graph whose vertices are supersingular elliptic curves and whose edges are isogenies of fixed degree l. It is immediate to prove that from each vertex there are exactly l+1 outgoing edges, while it is less obvious that such a graph is connected and that it has the Ramanujan property, a property about the spectrum of the adjacency matrix that implies that random walks very soon visit all vertices with the same probability. In our talk we look at a generalization of these graphs, namely graphs whose vertices are pairs (E,T), where E is a supersingular elliptic curve and T is some information on the n-torsion of E (e.g. a basis, a point, a subgroup) for fixed n. It is easy to notice that the secret keys in SIDH are exactly walks in such a generalized isogeny graph, and the public keys are vertices. These graphs can be multipartite, implying that the Ramanujan property is not always satisfied. By studying modular curves over mixed characteristics we relate isogeny graphs to geometric and cohomological objects, which allows us to prove the appropriate modification of the Ramanujan property. The properties of these generalized isogeny graphs are useful for a statistical zero knowledge proof of knowledge of an isogeny, which is part of a work with Basso, Connolly, De Feo, Fouotsa, Morrison, Panny, Patranabis and Wesolowski to generate elliptic curves with unknown endomorphisms.</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/news-and-events/events/lecture-series/heinz-hopf-prize-and-lectures.html">Heinz Hopf Symposium</a></div><br /><div class="event_speaker"> Lai-Sang Young (New York University)</div><div class="event_title">Heinz Hopf lecture II: Typical trajectories and observable events in deterministic and random dynamical systems</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://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">Felicitas Hörmann (German Aerospace Center (DLR))</div><div class="event_title">Distinguisher-Based Attacks on Linearized Reed-Solomon Codes <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />McEliece-like cryptosystems, which are at the core of code-based cryptography, exploit that efficient decoding of a suitable known code is easy but decoding in a random code is hard. The secret key is a fast decoder for a secret code, whereas the public key contains a disguised representation of the chosen code. Thus, it is crucial to ensure that the inherent structure of the secret code can be well hidden from the attacker when algebraic codes are used. We aim at building McEliece-like cryptosystems based on linearized Reed-Solomon (LRS) codes and their decoding properties in the sum-rank metric. We thus investigate their rich structure and appropriate disguising strategies. Since LRS codes generalize Reed-Solomon codes in the Hamming metric and Gabidulin codes in the rank metric, we show how known distinguishers for these code families carry over. In particular, we discuss the generalization of the square-code and Overbeck&#039;s attack. Surprisingly, LRS codes are not fully vulnerable to these attacks, which keeps them interesting for further cryptanalytic research and/or the design of cryptosystems.</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="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. Svitlana Mayboroda (ETH Z&uuml;rich, Switzerland)</div><div class="event_title">Wave Localization <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Waves of all kinds permeate our world. We are surrounded by light (electromagnetic waves), sound (acoustic waves), and mechanical vibrations. Quantum mechanics revealed that, at the atomic level, all matter has a wavelike character. And classical gravitational waves have been very recently detected. At the cutting edge of today’s science, it has become possible to manipulate individual atoms. This provides us with precise measurements of a world that exhibits myriad irregularities — dimensional, structural, orientational, and geometric— simultaneously. For waves, such disorder changes everything. In complex, irregular, or random media, waves frequently exhibit astonishing and mysterious behavior known as ‘localization’. Instead of propagating over extended regions, they remain confined in small portions of the original domain. The Nobel Prize–winning discovery of the Anderson localization in 1958 is only one famous case of this phenomenon. Yet, 60 years later, despite considerable advances in the subject, we still notoriously lack tools to fully understand localization of waves and its consequences. We will discuss modern understanding of the subject, recent results, and the biggest open questions.</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">Dr. Alejandro Rosales Ortiz (Universität Zürich, Switzerland)</div><div class="event_title">Working group step-reinforced random walks: Joint invariance principles</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, November 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/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">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"> Xiaoyu Zhang</div><div class="event_title">superspecial reductions of CM abelian varieties <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The CM points in a Shimura variety contain very important arithmetic information of the whole variety. The famous conjecture of André-Oort says that the Zariski closure of a family of CM points in a Shimura variety is in fact (a translation of) a subvariety of Hodge type. In this talk, we would like to say something about a variant of this conjecture mod a prime: take a p-power isogeny orbit C of a fixed CM abelian variety A, if A has superspecial reduction modulo a prime q, then a certain simultaneous reduction of elements in C (by action of a torus) is in fact surjective onto the set of all superspecial mod q abelian varieties. I will present these results and indicate the ideas of the proofs.</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://math.ethz.ch/sfs/news-and-events/data-science-seminar">ETH-FDS seminar </a></div><br /><div class="event_speaker"> Jakob Zech (Universität Heidelberg)</div><div class="event_title">Nonparametric Distribution Learning via Neural ODEs <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 explore approximation properties and statistical aspects of Neural Ordinary Differential Equations (Neural ODEs). Neural ODEs are a recently established technique in computational statistics and machine learning, that can be used to characterize complex distributions. Specifically, given a fixed set of independent and identically distributed samples from a target distribution, the goal is either to estimate the target density or to generate new samples. We first investigate the regularity properties of the velocity fields used to push forward a reference distribution to the target. This analysis allows us to deduce approximation rates achievable through neural network representations. We then derive a concentration inequality for the maximum likelihood estimator of general ODE-parametrized transport maps. By merging these findings, we are able to determine convergence rates in terms of both the network size and the number of required samples from the target distribution. Our discussion will particularly focus on target distributions within the class of positive $C^k$ densities on the $d$-dimensional unit cube $[0,1]^d$.</div><div class="event_time">16:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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">Prof. Dr. Denis Belomestny (Duisburg-Essen University)</div><div class="event_title">Preference-based reinforcement learning with financial applications <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Reinforcement learning (RL) algorithms aim to maximise the accumulated  reward for a suitably chosen reward function. However, designing such a reward function often requires  task-specific prior knowledge which may be not available in closed quantitative form.  To alleviate these issues, preference-based reinforcement learning algorithms  have been proposed that can directly learn from an expert’s preferences instead of a hand-designed numeric reward. In this talk I give an overview of preference-based reinforcement learning and illustrate its main principles on  examples from mathematical finance. In particular, I discuss what  type of human feedback can be assumed and how  preferences can be build in the optimization problem via penalisation.</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, November 17      </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"> Boris Pioline (LPTHE Paris)</div><div class="event_title">Counting BPS black hole micro-states with (mock) modular forms <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A central problem in quantum gravity is to get a quantitative microscopicinterpretation of the Bekenstein-Hawking entropy of black holes.In type II strings compactified on a Calabi-Yau manifold, BPS black holemicrostates are realized by bound states of D-branes wrappedalong complex submanifolds, or in mathematical terms by "stable coherentsheaves". String dualities predict that suitable generatingseries of indices counting such BPS states have modular properties, althoughthe mathematical origin of modularity is still mysterious.I will explain some recent progress in computing these BPS indices usingrelations to topological string theory and wall-crossing, andpresent strong evidence that modularity is indeed at work. Based on[arXiv:2301.08066] in collaboration withS. Alexandrov, S. Feyzbakshsh, A. Klemm and T. Schimannek, and sequel toappear.</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_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://sites.google.com/view/pm-seminar/home">Physical Mathematics Seminar</a></div><br /><div class="event_speaker"> Boris Pioline</div><div class="event_title">Counting BPS black hole micro-states with (mock) modular forms <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A central problem in quantum gravity is to get a quantitative microscopic interpretation of the Bekenstein-Hawking entropy of black holes.In type II strings compactified on a Calabi-Yau manifold, BPS black hole microstates are realized by bound states of D-branes wrappedalong complex submanifolds, or in mathematical terms by "stable coherent sheaves". String dualities predict that suitable generatingseries of indices counting such BPS states have modular properties, although the mathematical origin of modularity is still mysterious.I will explain some recent progress in computing these BPS indices using relations to topological string theory and wall-crossing, andpresent strong evidence that modularity is indeed at work. Based on [arXiv:2301.08066] in collaboration withS. Alexandrov, S. Feyzbakshsh, A. Klemm and T. Schimannek, and sequel to appear.</div><div class="event_time">14:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Saturday, November 18      </div>      <div class="day_content">        <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. Angela Gibney (University of Pennsylvania)</div><div class="event_title">The F-Conjecture <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The F-Conjecture is an old problem about the Mori Cone of the moduli space of curves.  In this talk I will describe the conjecture, its origins, what is known, and what we would know if it were to be true.  I’ll also describe some evidence that vertex operator algebras may play a role in refining our understanding of the problem.</div><div class="event_time">11:30 &bull; ETH Zentrum, Building ITS, Room  </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>';