var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-9"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-7"><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. 2</span>      <span style="float: right; text-align:right; width: 250px;">24.2 - 28.2.2025</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Spring Semester 2025</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, February 24      </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://theory.epfl.ch/seminar/">Theory and Combinatorics Seminar</a></div><br /><div class="event_speaker"> Neta Singer</div><div class="event_title">Better Approximation for Weighted k-Matroid <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We consider the problem of finding an independent set of maximum weightsimultaneously contained in k matroids over a common ground set. Thisk-matroid intersection problem appears naturally in many contexts, forexample in generalizing graph and hypergraph matching problems. In thispaper, we provide a (k+1)/(2ln2)-approximation algorithm for theweighted k-matroid intersection problem. This is the first improvementover the longstanding (k&#8722;1)-guarantee of Lee, Sviridenko and Vondrák(2009). Along the way, we also give the first improvement over greedyfor the more general weighted matroid k-parity problem.Our key innovation lies in a randomized reduction in which we solvealmost unweighted instances iteratively. This perspective allows us touse insights from the unweighted problem for which Lee, Sviridenko, andVondrák have designed a k/2-approximation algorithm. We analyze thisprocedure by constructing refined matroid exchanges and leveragingrandomness to avoid bad local minima.Based on joint work with Théophile Thiery.</div><div class="event_time">11:00 &bull; EPF Lausanne, INJ114</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"> Sophie  Achard (INRIA)</div><div class="event_title">Impact of spatial and temporal properties of multivariate time series on graph inference. <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Multivariate time series are most commonly observed in brain studies, where resting-state fMRI acquisitions provide observations of brain function over space and time. The brain can be modelled as a graph where nodes represent brain regions and edges correspond to functional connections between brain regions. In this talk I will show how temporal and spatial properties of the multivariate time series can drastically affect the inference of the graphs. Statistical properties will be illustrated for correlations. The impact of temporal properties is derived using complex wavelets, and a correction is proposed to account for long memory properties of the time series. Spatial properties are considered by proposing a novel nonparametric estimator of the correlation between groups of variables with arbitrary intra-group dependence and in the presence of noise. We illustrate these considerations with simulations as well as with real data using resting-state fMRI datasets from rats.</div><div class="event_time">15:15 &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://math.ethz.ch/s/symplectic-geometry-seminar">Symplectic Geometry Seminar</a></div><br /><div class="event_speaker"> Erman Çineli (ETH)</div><div class="event_title">Closed orbits of dynamically convex Reeb flows <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 discuss two results on the multiplicity problem for prime closed orbits of dynamically convex Reeb flows on the boundary of a star-shaped domain in R<sup>2n</sup>. The first result asserts that such a flow has at least n prime closed Reeb orbits, improving the previously known lower bound by a factor of two. The second main theorem is that when, in addition, the domain is centrally symmetric and the Reeb flow is non-degenerate, the flow has either exactly n or infinitely many prime closed orbits. This is a joint work with Basak Gurel and Viktor Ginzburg. </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>    </div>    <div class="day">      <div class="day_title">        Tuesday, February 25      </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://www.unil.ch/dsa/en/home/menuinst/seminaires--evenements/research-seminars.html">Talks in Actuarial Mathematics </a></div><br /><div class="event_speaker"> M. Fabien Baeriswyl (Operation department - HEC)</div><div class="event_title">Limiting results and large deviations of Poisson cluster processes <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 discuss the (hidden) regular variation of certain marked Poisson cluster point processes. (Hidden) regular variation of these processes is expressed as convergence on a space of point measures, where increasingly broad cones of possible limiting measures are successively removed. Using continuous mappings, we highlight that the then-obtained principles of hidden regular variation translates, in functional settings, to large deviation principles for trajectories of the functionals on Skorokhod space endowed with the right topology. This is a joint work with Olivier Wintenberger.  </div><div class="event_time">14:00 &bull; EPF Lausanne, Extranef 125</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"> Pavol Severa (UniGE)</div><div class="event_title"> Braided Hopf algebras (and other beasts) in the quasi-Hamiltonian world <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In Poisson geometry there are two basic "integration" constructions: any Poisson manifold integrates to a local symplectic groupoid and any Lie bialgebra to a Poisson-Lie group. These two facts were united by A. Weinstein and by K. Mackenzie and P. Xu to a picture, where at the top we have a double symplectic groupoid, at the bottom a Lie bialgebroid, and on the sides two Poisson groupoids. I will talk about a cute generalization of this to the world of quasi-Hamiltonian spaces, which form a braided monoidal category and thus somewhat entangle the picture. A part of the motivation is coming from braided Hopf algebras, and examples from moduli spaces of flat connections. In particular, the moduli space of flat G-connections on a punctured torus is a braided Hopf algebra in the G-quasi-Hamiltonian category.</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">Dr. Shrish  Parmeshwar (CY Cergy Paris Université)</div><div class="event_title">Global-in-time Vortex Configurations for the 2D Euler Equations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A long-standing topic of interest is to understand the desingularization problem in vortex dynamics for the incompressible 2D Euler equations: solutions of the system that approximate point vortices in the sense that the vorticity of the solution stays highly concentrated around a finite number of points on some interval of time. There are a large class of steady states that satisfy this behaviour, and also solutions that exhibit this behaviour dynamically on finite time intervals. We exhibit a solution of 2D Euler that is genuinely dynamic, and also retains this concentration of vorticity around points for all time: a configuration approximating two vortex pairs separating at a linear rate.</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">Prof. Dr. Chris Judge (Indiana University Bloomington)</div><div class="event_title">Hot spots on triangles <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In 1974 Jeff Rauch conjectured that for the generic initialtemperature distribution on an insulated object, the maximum of thetemperature distribution tends towards the insulated boundary. This conjecture is essentially equivalent to the assertionthat the second eigenfunction of the Neumann Laplacian has no interiorglobal extrema. This mathematical conjecture is still wide open. SugataMondal and I have shown that the conjecture holds for triangular objectsthus resolving Polymath 7.  In this talk, I will motivate and discuss the conjecture and describe some of the methods that have been used to attack it.</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, February 26      </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"> Adam Kanigowski (University of Maryland)</div><div class="event_title">Sparse Equidistribution Problems in 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_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"> Farrell Brumley (IUF & Sorbonne Université)</div><div class="event_title">Quantum ergodicity in higher rank for Benjamini-Schramm sequences of lattices <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The quantum ergodicity theorem of Schnirelman, Colin de Verdière, andZelditch states that on a compact Riemannian manifold with ergodicgeodesic flow, most eigenfunctions of high frequency distribute theirL2 mass according to the uniform measure. More recently, there hasbeen increasing interest in the delocalization properties ofeigenfunctions of bounded frequency on spaces of increasing volume. Aparticularly well-behaved setting is that of locally symmetric spaces,attached to cocompact lattices having uniform spectral gap in a fixednon-compact semisimple Lie group, which Benjamini-Schramm converge totheir commun universal cover.In rank one, this problem has seen tremendous progress. A discreteversion of this problem was solved in the breakthrough work ofAnantharaman-Le Masson for large regular graphs. Shortly thereafter analternative approach was given by Brooks-Le Masson-Lindenstrauss whichrelied critically on the construction of a wave propagator having goodspectral and geometric properties. The latter approach wassubsequently adapted to the setting of large hyperbolic surfaces by LeMasson-Sahlsten and then to higher dimensional hyperbolic manifolds byAbert-Bergeron-Le Masson. The kernels of these propagators aresupported on spheres or annuli, and (among other things) the argumentrequires good estimates on the intersection volumes of theirtranslates.In this talk, we shall present a higher rank construction of a wavepropagator, which generalizes the one given for PGL(3,\\Q_p) by CarstenPeterson in his thesis, and show how it can be used to prove quantumergodicity for locally symmetric spaces associated with classical realLie groups in the Benjamini-Schramm limit. In doing so, we repair anerror in our previous work on this topic for quotients of SL(n,\\R)with Jasmin Matz. Our approach to controlling intersection volumes isdue to Simon Marshall, and reduces to establishing deep estimates onthe Harish-Chandra spherical function. This is joint work with SimonMarshall, Jasmin Matz, and Carsten Peterson.</div><div class="event_time">13:00 &bull; EPF Lausanne, CE 1 100</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.math.uzh.ch/mat760">Ergodic theory and dynamical systems seminar</a></div><br /><div class="event_speaker">Prof. Dr. Chris Judge (Indiana University)</div><div class="event_title">Shrinking targets for affine self-diffeomorphisms of translation surfaces <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The affine self-diffeomorphism group of a translation surface can be rather large. For example, the affine diffeos of a 2-torus contain a lattice.  In the case of a torus $T$, Ghosh, Gorodnik, and Nevo proved that for any $\\eta &gt; 0$, for almost every $y \\in T$ and for every $x \\in T$, there exist infinitely many $\\gamma \\in SL_2(Z)$ so that $\\| \\gamma x- y \\|\\leq \\|\\gamma\\|^{-1-\\eta}$. We show that a similar result holds for translation surfaces with the lattice property. This is joint work with Josh Southerland.</div><div class="event_time">13:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room E 33.1</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">Complex abelian varieties and their moduli X <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Piecewise polynomials and Chow rings</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/sam/news-and-events/zhacm-colloquia">Zurich Colloquium in Applied and Computational Mathematics</a></div><br /><div class="event_speaker">Prof. Dr. Philippe Ciarlet (Institut für Mathematik, Universität Zürich)</div><div class="event_title">A two-dimensional nonlinear shell model of Koiter\'s type <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />As is well-known, Koiter\'s model is often used in numerical simulations, because it is a two-dimensional model that captures well the "membrane-dominated" and "flexural-dominated" effects that arise in a nonlinearly elastic shell subjected to applied forces and specific boundary conditions.  Finding a satisfactory existence theory for this nonlinear shell model has stood as an open problem for a very long time.  The present work, which is a joint work with Cristinel Mardare, provides a two-dimensional model that preserves all the virtues of Koiter\'s model, while being in addition amenable to a satisfactory existence theory.  More precisely, our new two-dimensional mathematical model for a nonlinearly elastic shell takes the form of a minimization problem with a stored energy function that is polyconvex and orientation-preserving, and more generally satisfies all the other assumptions of John Ball\'s existence theorem.  In addition, the most noteworthy feature of this model is that it is "of Koiter\'s type", in the sense that for a specific class of deformations that are "to within the first order" identical to those introduced by W.T. Koiter for defining his model, the "lowest order part" of its stored energy function coincides with the stored energy function of Koiter\'s model.</div><div class="event_time">16:30 &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_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. Titus Lupu (LPSM, Sorbonne Université)</div><div class="event_title">Relation between the geometry of sign clusters of the 2D GFF and its Wick powers <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In 1990 Le Gall showed an asymptotic expansion of the epsilon-neighborhood of a planar Brownian trajectory (Wiener sausage) into powers of 1/|log eps|, that involves the renormalized self-intersection local times. In my talk I will present an analogue of this in the case of the 2D GFF. In the latter case, there is an asymptotic expansion of the epsilon-neighborhood of a sign cluster of the 2D GFF into half-integer powers of 1/|log eps|, with the coefficients of the expansion being related to the renormalized (Wick) powers of the GFF.</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, February 27      </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"> Giacomo Colombo (ETH Zürich)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde/detail/bernoullis-tafelrunde-giacomo-colombo-eth-zuerich/">Bernoulli encounters obstacles (and their singular set)</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We will do a brief overview on the main questions that people try to answer in free boundary problems, with a focus on results on the singular set in the obstacle problem. abstract</div><div class="event_time">12:15 &bull; Universität Basel, Spiegelgasse 5, Seminar Room 05.001</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/zahlentheorie/">Seminar Zahlentheorie</a></div><br /><div class="event_speaker"> Alina Ostafe (UNSW)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/number-theory-seminar-alina-ostafe-university-of-new-south-wales-1-1-1/">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 />Title: On some matrix counting problems Abstract: We consider some questions of arithmetic statistics for matrices of a given rank or fixed determinant or characteristic polynomial, whose entries are parametrised by arbitrary polynomials over the integers. In particular, some of our results improve a recent bound of V. Blomer and J. Li (2022) for counting matrices of given rank that are parametrised by monomials. Joint works with Philipp Habegger, Ali Mohammadi and Igor Shparlinski. Spiegelgasse 5, Seminarraum 05.002</div><div class="event_time">14:15 &bull; Universität Basel</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/kolloquium">Perlen-Kolloquium</a></div><br /><div class="event_speaker"> Prof. Mathias Drton (Technical University Munich)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/perlenkolloquium-prof-mathias-drton-technical-university-munich/">Identification and Statistical Estimation of Graphical Continuous Lyapunov Models</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The ultimate aim of many data analyses is to infer cause-effect relationships between random variables of interest. While much of the available methodology for addressing causal questions relies on structural causal models, these models are best suited for systems without feedback loops. Extensions to accommodate feedback have been proposed but often result in models that are challenging to interpret. In this talk, we present an alternative approach to structural causal modeling: graphical continuous Lyapunov models. This framework offers a novel perspective on modeling causally interpretable dependence structures in multivariate data by treating each independent observation as a one-time cross-sectional snapshot of an underlying temporal process. Specifically, we focus on models based on multivariate Ornstein-Uhlenbeck processes in equilibrium, which yield Gaussian distributions where the continuous Lyapunov equation determines the covariance matrix. Within this framework, each graphical model assumes a sparse drift matrix whose support is encoded by a directed graph. We will discuss initial results on the identifiability of sparse drift matrices and explore methods for their regularized estimation, highlighting the potential as well as challenges in developing graphical continuous Lyapunov models as an interpretable tool for causal analysis in systems with feedback loops.</div><div class="event_time">16:15 &bull; Universität Basel, DMI, Spiegelgasse 5, 4051 Basel, Seminar Room 05.002</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://stat.ethz.ch/events/research_seminar">Research Seminar in Statistics</a></div><br /><div class="event_speaker"> David M. Blei (Columbia University)</div><div class="event_title">Joint talk ETH-FDS Seminar - Research Seminar on Statistics:"Scaling and Generalizing Approximate Bayesian Inference" <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A core problem in statistics and machine learning is to approximatedifficult-to-compute probability distributions. This problem isespecially important in Bayesian statistics, which frames allinference about unknown quantities as a calculation about a conditional distribution. In this talk I review and discussinnovations in variational inference (VI), a method that approximates probability distributions through optimization. VI has been used in myriad applications in machine learning and Bayesian statistics.After quickly reviewing the basics, I will discuss two lines ofresearch in VI.  I first describe stochastic variational inference, an approximate inference algorithm for handling massive datasets, anddemonstrate its application to probabilistic topic models of millions of articles. Then I discuss black box variational inference, a more generic algorithm for approximating the posterior.  Black box inference  applies to many models but requires minimal mathematical work to implement.  I will demonstrate black box inference on deep exponential families---a method for Bayesian deep learning---and describe how it enables powerful tools for probabilistic programming.Finally, I will highlight some more recent results in variationalinference, including statistical theory, score-based objectivefunctions, and interpolating between mean-field and fully dependent variational families.</div><div class="event_time">16:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room D 1.2</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"> David M. Blei (Columbia University)</div><div class="event_title">Joint talk ETH-FDS Seminar - Research Seminar on Statistics: "Scaling and Generalizing Approximate Bayesian Inference" <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A core problem in statistics and machine learning is to approximatedifficult-to-compute probability distributions. This problem isespecially important in Bayesian statistics, which frames all inference about unknown quantities as a calculation about a conditional distribution. In this talk I review and discussinnovations in variational inference (VI), a method that approximatesprobability distributions through optimization. VI has been used inmyriad applications in machine learning and Bayesian statistics.After quickly reviewing the basics, I will discuss two lines of research in VI.  I first describe stochastic variational inference, an approximate inference algorithm for handling massive datasets, anddemonstrate its application to probabilistic topic models of millions of articles. Then I discuss black box variational inference, a more generic algorithm for approximating the posterior.  Black box inference  applies to many models but requires minimal mathematical work to implement.  I will demonstrate black box inference on deepexponential families---a method for Bayesian deep learning---anddescribe how it enables powerful tools for probabilistic programming.Finally, I will highlight some more recent results in variationalinference, including statistical theory, score-based objectivefunctions, and interpolating between mean-field and fully dependent variational families.</div><div class="event_time">16:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG , Room D 1.2</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_be"><a class="external" href="https://www.unibe.ch">Universität Bern</a></div><div class="event_type"><a class="external" href="https://www.imsv.unibe.ch/research/talks/colloquia/index_eng.html">Colloquia on Probability and Statistics </a></div><br /><div class="event_speaker"> Anna Shalova (TU Eindhoven)</div><div class="event_title"><a class="external" href="https://www.imsv.unibe.ch/research/talks/schedule/index_eng.html">Solutions of stationary McKean-Vlasov equation on a sphere </a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We study stationary solutions of McKean-Vlasov equation on a high-dimensional sphere. We extend the equivalence of the energetic problem formulation to the manifold setting and characterize critical points of the corresponding free energy functional. Employing the properties of spherical convolution we study the bifurcation branches around the uniform state. We also give a sufficient condition for an existence of a discontinuous transition point in terms of the interaction kernel and compare it to the Euclidean setting. We illustrate our findings on the particle system arising from the transformer models. The talk is mostly based on the joint work with André Schlichting: “Solutions of stationary McKean-Vlasov equation on a high-dimensional sphere and other Riemannian manifolds”, arXiv:2412.14813 (2024).</div><div class="event_time">16:15 &bull; Universität Bern, IMSV, Alpeneggstrasse 22, 3012 Bern, Hörraum -203</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Friday, February 28      </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"> Boris Bukh (Carnegie Mellon University)</div><div class="event_title">Discrete 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_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/number-theory-seminar">Number Theory Seminar</a></div><br /><div class="event_speaker">Dr. Ananyo  Kazi (UniDistance Suisse)</div><div class="event_title">Twisted triple product p-adic L-function for finite slope families and a p-adic Gross–Zagier formula <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In the theory of p-adic L-functions a p-adic Gross–Zagier formula gives interpretation to special values of p-adic L-functions outside the region of interpolation using p-adic integration. Seen as a first step towards "explicit reciprocity laws" they have important applications towards proving various instances of the Bloch-Kato conjecture. We construct a p-adic twisted triple product L-function associated to finite slope families of Hilbert modular forms, assuming p unramified in the totally real fields. In joint work with Ting-Han Huang, we prove a p-adic Gross–Zagier formula for this L-function for a pair of an elliptic modular form and a quadratic Hilbert modular form. This generalises work of Blanco-Chacon and Fornea for the case of Hida families, and we overcome a technical assumption in their work of p being split in the quadratic field.</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_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"> Sonia  Petrone (Bocconi University, Milan)</div><div class="event_title">From prediction to inference: Bayesian uncertainty quantification for recursive predictive algorithms <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We are used to go from inference to prediction.  In a predictive approach,  one would directly reason on the predictive rule.  Yet,  many predictive algorithms lack formal uncertainty quantification. This talk presents a methodology for providing Bayesian uncertainty quantification for a class of recursive predictive algorithms that includes, for example, popular online gradient descent with streaming data.We read these algorithms as Bayesian predictive learning rules, which allows us reveal their  implicit modeling assumptions and provide uncertainty quantification through a new asymptotic expression of the posterior distribution. The key for these results lies in the Bayesian predictive approach, where inferential model are deduced from the predictive rule. </div><div class="event_time">15:15 &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://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Qaasim Shafi (Universität Heidelberg)</div><div class="event_title">Descendant tropical correspondence theorems and applications <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br /> I will present a result connecting higher genus descendant logarithmic Gromov-Witten invariants of toric surfaces to refined counts of tropical curves. I will then discuss some applications. First, how it can be used to relate higher genus descendant invariants of logCalabi-Yau surfaces with quantum scattering diagrams, generalising an expectation coming from mirror symmetry. I will then briefly mention how these tropical correspondence theorems may help with computing the quantum cohomology ring of the Hilbert scheme of points on an ellipticsurface. This is based on joint work Patrick Kennedy-Hunt and AjithUrundolil Kumaran, as well as conversations with Georg Oberdieck. </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>';