var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-5"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-3"><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. 5</span>      <span style="float: right; text-align:right; width: 250px;">17.3 - 21.3.2025</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, March 17      </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"> Alexey Gordeev</div><div class="event_title"> On a travelling salesman problem in the unit cube <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />onsider a variant of the travelling salesman problem which asks for a closed tour of minimal weight through n given points in the k-dimensional unit cube [0, 1]^k, where the weight of the segment connecting two points is the k-th power of its Euclidean length. In 1992, Bollobás and Meir showed that there always exists a tour of weight at most c_k * k^(1 / 2). Remarkably, this bound does not depend on n, the number of points. They proved that one can take c_k = 9 * (2 / 3)^(1 / k) and conjectured that the best possible constant is c_k = 2^(1 / k), which corresponds to sets of points clustered around two opposite vertices of the unit cube. The conjecture has been proved only for k = 2. Recently, Balogh, Clemen and Dimitrescu disproved the conjecture for k = 3 by constructing a set of points with the minimal tour of weight 2^(7 / 6). They also proved that one can take c_k = 2.91 + o_k(1).I will show how to improve this further to c_k = 2.65 + o_k(1). I will also discuss analogous problems for spanning trees and perfect matchings which, perhaps contrary to algorithmic intuition, turn out to be quite non-trivial in this setting.</div><div class="event_time">12:15 &bull; EPF Lausanne, INJ114</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-mathematical-physics">Talks in Mathematical Physics</a></div><br /><div class="event_speaker"> Alex Takeda (Uppsala University)</div><div class="event_title">Formality of Y-infinity algebras and operations in string topology <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will define a certain type of properadic algebra called a Y-infinity algebra, which is an A-infinity algebra together with higher structure maps encoding a certain type of Poincaré duality structure. In particular, the algebra of chains on the based loop space of any oriented manifold is canonically endowed with this type of structure. By using the formalism of properadic Kaledin classes, we can study these algebraic structures and detect their formality, or lack thereof. I will also explain the relation between these algebraic structures and string topology operations, and how Y-infinity formality plays a role in understanding these operations. This talk is about joint works with M. Rivera, Z. Wang and C. Emprin.</div><div class="event_time">13:30 &bull; ETH Zentrum, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 25</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/symplectic-geometry-seminar">Symplectic Geometry Seminar</a></div><br /><div class="event_speaker"> Rohil Prasad</div><div class="event_title">Invariant subsets in three-dimensional energy surfaces II   <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The goal of this series of talks is to present a proof, at a higher level of detail than usual, of the following theorem. Let H be any smooth function on R^4 and let Y be any compact and regular level set. Then Y admits an infinite family of proper compact subsets that are invariant under the Hamiltonian flow, which in addition have dense union in Y. This improves on a 2018 result by Fish-Hofer, which showed the existence of one proper invariant subset. Related results were proved jointly with Dan Cristofaro-Gardiner for area-preserving surface diffeomorphisms and 3D Reeb flows. I will mention them if there is time. </div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/mpseminar/seminar.html">Séminaire de Mathématique Physique </a></div><br /><div class="event_speaker"> Nikolai  Bobenko  (UNIGE)</div><div class="event_title">Dimers and M-Curves: Limit Shapes from Riemann Surfaces <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We present a general approach for the study of dimer model limit shape problems via variational and integrable systems techniques. In particular we deduce the limit shape of the Aztec diamond and the hexagon for quasi-periodic weights through purely variational techniques. Putting an M-curve at the center of the construction allows one to define weights and algebro-geometric structures describing the behavior of the corresponding dimer model. We extend the quasi-periodic setup of our previous work to include a diffeomorphism from the spectral data to the liquid region of the dimer. Our novel method of proof is purely variational and exploits a duality between the dimer height function and its dual magnetic tension minimizer and applies to dimers with gas regions. We apply this to the Aztec diamond and hexagon domains to obtain explicit expressions for the complex structure of the liquid region of the dimer as well as the height function and its dual. We compute the weights and the limit shapes numerically using the Schottky uniformization technique. Simulations and predicted results match completely.</div><div class="event_time">16:15 &bull; Université de Genève, Conseil Général 7-9, Room 1-15</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_be"><a class="external" href="https://www.unibe.ch">Universität Bern</a></div><div class="event_type"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Mathematisches Kolloquium </a></div><br /><div class="event_speaker">Prof. Dr. Jaroslaw Buczy&#324;ski (IMPAN Warshaw)</div><div class="event_title"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Three stories of Riemannian and holomorphic manifolds</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Compact holomorphic manifolds and Riemannian manifolds invite you all to participate in their three epic stories. In the first tale, the main character is going to be a compact holomorphic manifold, and as in every story, there will be some action going on. More specifically, the group of invertible complex numbers, or even better, several copies of those, act on the manifold. The spirit of late Andrzej Bia&#322;ynicki-Birula until this day helps us to comprehend what is going on. The second story is a tale of holonomies, it begins with "a long time ago,..." and concludes with "... and the last missing piece of this mystery is undiscovered til this day". The protagonist of this part is a quaternion-Kahler manifold, while the legacy of Marcel Berger is in the background all the time. In the third part we meet legendary distributions, which are subbundles in the tangent bundle of one of our main characters. Among others, distributions can be foliations, or contact distributions, which like yin and yang live on the opposite sides of the world, yet they strongly interact with one another. Ferdinand Georg Frobenius is supervising this third part. Finally, in the epilogue, all the threads and characters so far connect in an exquisite theorem on classification of low dimensional complex contact manifolds. In any dimension the analogous classification is conjectured by Claude LeBrun and Simon Salamon, while in low dimensions it is proved by Jaros&#322;aw Wi&#347;niewski, Andrzej Weber, in a joint work with the narrator.</div><div class="event_time">17:15 &bull; Universität Bern, Sidlerstrasse 5, 3012 Bern, Room B6</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, March 18      </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"> Yash  Lodha (University of Hawaii at Manoa)</div><div class="event_title">Uniform simplicity, group actions on the circle, and Ulam width <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A fundamental notion in group theory, which originates in an article of Ulam and von Neumann from 1947 is uniform simplicity.A group is uniformly simple if there is a natural number n such that for each pair of nontrivial elements f,g, the element f can be expressed as a product of at most n conjugates of g, g^{-1}. The smallest such n is called the Ulam width.In this talk, I will describe this notion and describe for each natural number n, a construction of a group of homeomorphisms of the circle that is finitely presented, infinite and simple, whose Ulam width is larger than n.</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"> Georgiy  Shevchenko  (Kyiv School of Economics)</div><div class="event_title">Stratonovich stochastic differential equation with power non-linearity: (non)-uniqueness and selection problem <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br /> I will review results regarding a Stratonovich stochastic differential equation$$X_t=X_0+\\int_0^t |X_s|^\\alpha\\circ d B_s,$$which was introduced in the physical literature under the name ”heterogeneous diffusion process”. It turns out that equation has properties quite different from its Ito counterpart.Namely, we show that for $\\alpha\\in(0,1)$ it has infinitely many strong solutions spending zero time at zero. They are given by $X^\\theta = \\bigl((1-\\alpha)B^\\theta+(X_0)^{1-\\alpha} \\bigr)^{1/(1-\\alpha)}$, where for $\\theta\\in(-1,1)$, $B^\\theta$ is the $\\theta$-skew Brownian motion, and $(x)^{\\gamma} = |x|^\\gamma \\operator name{sign} x$. It appears that there are no other homogeneous strong Markov solutions to the equation. To address the non-uniqueness, we consider a perturbation of the equation by a small independent noise. It appears that the solution to such equations converge to the solution of initial equation corresponding to $\\theta=0$, i.e. the physically symmetric case.  </div><div class="event_time">14:00 &bull; EPF Lausanne, Extranef 126</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/annonces/groupes-geometrie">Groupes et Géométrie </a></div><br /><div class="event_speaker"> Yash  Lodha (University of Hawaii at Manoa)</div><div class="event_title">Mini course: Orderability and groups of dynamical origin <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The study of bi-orderable groups has a long history that goes back to seminal work of Dedekind, H older and Hilbert. The study of left orderable groups has more modern origins, and the notion provides a remarkable characterization of whether a countable group admits a faithful action by orientation preserving homeomorphisms on the real line.In this mini course we will introduce and study these notions.The first lecture will be an introduction to left orderable and bi-orderable groups,and shall describe an algebraic point of view.The second lecture will feature various examples of groups of dynamical origin that naturally emerge as groups of homeomorphisms of the real line and the circle.The third lecture will describe connections with the analytic notions of second bounded cohomology, rotation numbers, stable commutator length and quasi-morphisms.The fourth lecture will focus on the space of left orders on a countable group and the Witte-Morris theorem.Throughout the mini course, I will discuss open problems and new directions of research.</div><div class="event_time">14:00 &bull; Université de Genève, Conseil Général 7-9, Room 6-13</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/analysis-seminar">Analysis Seminar</a></div><br /><div class="event_speaker">Dr. Ahmed  Bou-Rabee (Courant Institute)</div><div class="event_title">Homogenization with critical disorder <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Homogenization is the approximation of a complex, “disordered” system by a simpler, “ordered” one. A natural example is random walk on a grid. Simple random walk on large scales approximates a Brownian motion. But what if some edges are more likely to be traversed than others? I will discuss recent advances in the theory of quantitative homogenization which make it possible to analyze the random walk with drift and other models in statistical physics. Joint work with Scott Armstrong and Tuomo Kuusi.</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"> Rohil Prasad</div><div class="event_title"> Invariant subsets in three-dimensional energy surfaces III <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The goal of this series of talks is to present a proof, at a higher level of detail than usual, of the following theorem. Let H be any smooth function on R^4 and let Y be any compact and regular level set. Then Y admits an infinite family of proper compact subsets that are invariant under the Hamiltonian flow, which in addition have dense union in Y. This improves on a 2018 result by Fish-Hofer, which showed the existence of one proper invariant subset. Related results were proved jointly with Dan Cristofaro-Gardiner for area-preserving surface diffeomorphisms and 3D Reeb flows. I will mention them if there is time. </div><div class="event_time">15:15 &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://www.math.uzh.ch/mat075.1">Zurich Graduate Colloquium</a></div><br /><div class="event_speaker">Baptiste Seraille (ETH)</div><div class="event_title">What is... the Anosov-Katok Construction? <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 present the Anosov-Katok construction and motivate it by presenting/recalling celebrated results of Poincaré, Birkhoff and Franks. If time permits we will see some recent applications of this construction in the field of symplectic topology.</div><div class="event_time">16:30 &bull; UZH Zentrum, Building KO2, Room F 150</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, March 19      </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_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"> Yash  Lodha (University of Hawaii at Manoa)</div><div class="event_title">Mini course: Orderability and groups of dynamical origin <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The study of bi-orderable groups has a long history that goes back to seminal work of Dedekind, H older and Hilbert. The study of left orderable groups has more modern origins, and the notion provides a remarkable characterization of whether a countable group admits a faithful action by orientation preserving homeomorphisms on the real line.In this mini course we will introduce and study these notions.The first lecture will be an introduction to left orderable and bi-orderable groups,and shall describe an algebraic point of view.The second lecture will feature various examples of groups of dynamical origin that naturally emerge as groups of homeomorphisms of the real line and the circle.The third lecture will describe connections with the analytic notions of second bounded cohomology, rotation numbers, stable commutator length and quasi-morphisms.The fourth lecture will focus on the space of left orders on a countable group and the Witte-Morris theorem.Throughout the mini course, I will discuss open problems and new directions of research.</div><div class="event_time">10:30 &bull; Université de Genève, Conseil Général 7-9, Room 1-05</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://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">Dr. Tanja Schindler (Jagiellonian University/University of Exeter)</div><div class="event_title">Trimmed laws of large numbers for different dynamical systems <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Trimming, i.e. removing the largest summands of a sum of identically distributed (iid) random variables, has a long tradition to prove limit theorems which are not valid if one considers the untrimmed sum - one example is the strong law of large numbers for random variables with an infinite mean or in case of ergodic transformations Birkhoff\'s ergodic theorem. In this talk I will compare different dynamical systems, e.g. piecewise expanding interval maps and irrational rotations with the results for iid random variables regarding weak and strong laws of large numbers after trimming. This will be a somewhat expository talk.</div><div class="event_time">13:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Prof. Dr. Hsian-Hua Tseng (Ohio State University)</div><div class="event_title">Gromov-Witten theory of Hilbert schemes of points on the affine plane I <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The goal of these two talks is to discuss results on equivariant Gromov-Witten invariants of Hilbert schemes of points on C^2. In the first talk, we present a summary of results in genus 0 due to Okounkov-Pandharipande. We also discuss some aspects of determining higher genus theory using Givental-Teleman reconstruction. In the second talk, we discuss recent progress on a detailed study of genus 1 theory.</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_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"> Yash  Lodha (University of Hawaii at Manoa)</div><div class="event_title">Mini course: Orderability and groups of dynamical origin <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The study of bi-orderable groups has a long history that goes back to seminal work of Dedekind, H older and Hilbert. The study of left orderable groups has more modern origins, and the notion provides a remarkable characterization of whether a countable group admits a faithful action by orientation preserving homeomorphisms on the real line.In this mini course we will introduce and study these notions.The first lecture will be an introduction to left orderable and bi-orderable groups,and shall describe an algebraic point of view.The second lecture will feature various examples of groups of dynamical origin that naturally emerge as groups of homeomorphisms of the real line and the circle.The third lecture will describe connections with the analytic notions of second bounded cohomology, rotation numbers, stable commutator length and quasi-morphisms.The fourth lecture will focus on the space of left orders on a countable group and the Witte-Morris theorem.Throughout the mini course, I will discuss open problems and new directions of research.</div><div class="event_time">14:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-05</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/labs/hessbellwald-lab/seminar/epfl-topology-seminar-fall-2024/">Séminaire de Topologie </a></div><br /><div class="event_speaker"> Bruno Gavranovi&#263; (independent researcher)</div><div class="event_title"><a class="external" href="https://www.epfl.ch/labs/hessbellwald-lab/seminar/epfl-topology-seminar-fall-2024/">Category Theory &#8745; Deep Learning: the past, the present, and the future</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Despite its remarkable success, deep learning is a young field. Like the early stages of many scientific disciplines, it is permeated by ad-hoc design decisions. From the intricacies of the implementation of backpropagation, through new and poorly understood phenomena such as double descent, scaling laws or in-context learning, to a growing zoo of neural network architectures — there are few unifying principles in deep learning, and no uniform and compositional mathematical foundation. In this talk, I will give you a sense of what the necessary components of such a foundation are, the role that category theory plays in it, and the kind of models and new capabilities this systematic approach unlocks.</div><div class="event_time">14:15 &bull; <a class="external" href="https://plan.epfl.ch/?room==CM%201%20416">EPF Lausanne</a></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"> Alberto Enciso (ICMAT Madrid)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-analysis-and-mathematical-physics-alberto-enciso-icmat-madrid/">Steady Euler flows via a topology-preserving convex integration scheme</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk I will review some results concerning the existence of stationary solutions to the 3D Euler equations that are topologically equivalent, in some sense, to a given smooth divergence-free field. The rule of thumb is that, for "most" fields, there does not exist a C^1 topologically equivalent steady Euler flow, but there aways exists a (weakly) topologically equivalent steady Euler flow of class C^lpha.</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. Hassan Ou-azzou (Universität St.Gallen)</div><div class="event_title">Equivalence of Polycyclic and Skew Polycyclic Codes (Part 2) <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this presentation, we study the equivalence of families of skew polycyclic codes associated with the skew polynomial \\( x^n - \\vec{a}(x)\\), with \\(\\vec{a}=(a_0,a_1,\\ldots,a_{n-1}) \\in \\mathbb{F}_q^n,\\) for short we say skew \\((\\vec{a},\\sigma)\\)-polycyclic code, where \\(\\sigma\\) is automorphism of \\(\\mathbb{F}_q.\\) We begin with the case of skew \\(\\ell\\)-trinomial codes associated with a trinomial \\(x^n - a_{\\ell} x^{\\ell} - a_0\\) (for some \\(0&lt; \\ell &lt;n\\)), after which we generalize our results to general skew polycyclic codes. We introduce an equivalence relation called {\\(n\\)-equivalence}, which extends the known notion of \\(n\\)-equivalence for skew constacyclic codes. We compute the number of \\(n\\)-equivalence classes for this relation and provide conditions under which two families of polycyclic (or \\(\\ell\\)-trinomial) codes are equivalent. Finally, we provide some examples as an application.</div><div class="event_time">15:15 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 28</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/geometry-seminar">Geometry Seminar</a></div><br /><div class="event_speaker"> Raphael Appenzeller (Universität Heidelberg)</div><div class="event_title">Characterizing hyperbolicity via game theory <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The cop numbers are two new integer-valued invariants of finitely generated groups defined in terms of a two player pursuit game played on Cayley graphs. We use the cop numbers to give a new characterization of hyperbolic groups and virtually free groups. We discuss potential applications and recent progress on remaining open questions. This is joint work with Kevin Klinge.</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/mat675.1">PDE and Mathematical Physics</a></div><br /><div class="event_speaker">Prof. Dr. Andras Vasy (Stanford University)</div><div class="event_title">Spectral theory for Dirac type operators on asymptotically Minkowski spaces and the spectral action principle in Lorentzian signature <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will discuss a microlocal analysis approach to spectral theory on asymptotically Minkowski spaces both for scalar wave operators and also for Dirac type operators. This in turn gives rise to complex powers of the operators, allowing for the analysis of a spectral zeta function, relating its residues to geometric information. This is joint work with Nguyen Viet Dang and Michal Wrochna. Special time: Wednesday, 16:15 Special room: ETH LFW B3</div><div class="event_time">16:15 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 46</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/sam/news-and-events/zhacm-colloquia">Zurich Colloquium in Applied and Computational Mathematics</a></div><br /><div class="event_speaker">Prof. Dr. Tulin Kaman (University of Arkansas, USA)</div><div class="event_title">Statistical convergence of turbulence <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Turbulent mixing induced by hydrodynamic instabilities occurs when two fluids of different densities, velocities, and viscosities interact. Theoretical, experimental, and numerical efforts to understand and predict the dynamics of hydrodynamic instabilities are very important for science and engineering applications. Statistical convergence and turbulence quantification are crucial for achieving reliable and accurate modeling and simulations. In this talk, we present an increasingly accurate and robust front-tracking/ghost-fluid method with higher-order weighted essentially non-oscillatory schemes used for the numerical simulations of Rayleigh-Taylor and Richtmyer-Meshkov Instabilities. We investigate the time evolution of velocity fields and fluctuations for different configurations to explore the scaling law of the energy spectrum. </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. Alejandro Rosales Ortiz  (Universität Zürich, Switzerland)</div><div class="event_title">Graduate Workshop Reinforcement</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, March 20      </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"> Remo Von Rickenbach (Universität Basel)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde/detail/bernoullis-tafelrunde-remo-von-rickenbach-universitaet-basel-1/">Bernoulli Explains Nonlinear Approximation</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Many problems from physics or engineering result in partial differential equations. In both cases, the unknown function \\(u\\) can, in most practically relevant applications, only be approximated numerically. Therefore, it is essential to use efficient algorithms to approximate \\(u\\) at as low costs as possible. To build efficient algorithms, one first needs to understand how well a function of a given regularity can be approximated. For example, by using finite elements of grid size \\(h\\) on the unit interval \\(I\\), it is well established that the approximation error decays as \\begin{align*} \\inf_{v_h \\in V_h} \\|u - v_h\\|_{L^2(I)} \\leq C h^s \\|u\\|_{H^{s}(I)}, \\quad 0 \\leq s \\leq d, \\end{align*} where \\(d \\in \\mathbb{N}\\) is the polynomial order of the trial functions involved. However, what can we say about the approximation order if \\(u\\) is only piecewise regular, but admits a singularity and is therefore not in \\(H^{s}(I)\\)? For this, adaptive schemes, which rely on the concept of \\emph{nonlinear approximation}, need to be studied. In this talk, some basic concepts and examples of approximation theory will be introduced and we will characterise the approximation spaces with respect to some common basis systems. In particular, we will see that the approximation spaces with respect to nonlinear approximation by wavelet bases contain Besov spaces which are strictly larger than the corresponding, classical finite element approximation spaces, showing that adaptive schemes strictly outperform classical schemes in the case of limited regularity. abstract</div><div class="event_time">12:15 &bull; Universität Basel, Spiegelgasse 5, 05.001</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://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"> Cécile  Gachet  (Bochum)</div><div class="event_title">The nef, movable, and effective cones:From Mori Dream Spaces to Calabi—Yau pairs. <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />To a complex projective variety come various convex cones attached, whose shapes encode knowledge of fibrations, birational contractions, symmetries of the initial variety, and more. The nef, movable, and effective cones all arise in this way. As they encode different, but related information, one can wonder how they overall relate: A classical result along those lines is due to Hu and Keel, and states that a variety whose nef and movable cone both are rational polyhedral also has, under additional assumptions, a rational polyhedral effective cone. This result made precise leads to the study of so-called Mori Dream Spaces, which are a source of motivation for the work I plan to present, and will be the focus of the first half of the talk.In the second half of the talk, I will report on recent joint work with H.-Y. Lin, I. Stenger, and L. Wang. Inspired by the Morrison-Kawamata cone conjecture, we introduce an effective cone conjecture, and relate it to the nef and movable cone conjectures. If time allows, we will explain how to harness implications between these three cone conjectures in concrete geometric situations.</div><div class="event_time">13:15 &bull; EPF Lausanne, CM 1517</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://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">Dr. Léo Mathis (Goethe University Frankfurt, DE)</div><div class="event_title">Non centered Gaussian determinants with Gaussian zonoids <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A Theorem of Vitale, Molchanov and Wespi, states that the expected absolute determinant of a random matrix with independent columns is equal to the mixed volume of some convex bodies called zonoids. In the case where the columns of the matrix are centered Gaussian, the corresponding zonoids are ellipsoids and this was studied by Kabluchko and Zaporozhets. The case of non centered Gaussian vectors, however, remains relatively unstudied. The convex bodies we obtain in this case, which I call Gaussian zonoids, are not ellipsoids. In this talk, I will show you what a Gaussian zonoid looks like and how one can approximate it with an ellipsoid. At the level of random determinants, this allows to approximate expectation of non centered Gaussian determinants with centered ones. If time allows, I will show how this applies to Gaussian random fields. Namely, I will show how one can give a quantitative estimate of the concentration of a small Gaussian perturbation of a hypersurface.</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/sfs/news-and-events/data-science-seminar">ETH-FDS seminar </a></div><br /><div class="event_speaker"> Stefan  Wager (Stanford University)</div><div class="event_title">Joint talk ETH-FDS Seminar - Research Seminar on Statistics: "Optimal Mechanisms for Demand Response: An Indifference Set Approach" <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The time at which renewable (e.g., solar or wind) energy resources produce electricity cannot generally be controlled. In many settings, consumers have some flexibility in their energy consumption needs, and there is growing interest in demand-response programs that leverage this flexibility to shift energy consumption to better match renewable production -- thus enabling more efficient utilization of these resources. We study optimal demand response in a model where consumers operate home energy management systems (HEMS) that can compute the "indifference set" of energy-consumption profiles that meet pre-specified consumer objectives, receive demand-response signals from the grid, and control consumer devices within the indifference set. For example, if a consumer asks for the indoor temperature to remain between certain upper and lower bounds, a HEMS could time use of air conditioning or heating to align with high renewable production when possible. Here, we show that while price-based mechanisms do not in general achieve optimal demand response, i.e., dynamic pricing cannot induce HEMS to choose optimal demand consumption profiles within the available indifference sets, pricing is asymptotically optimal in a mean-field limit with a growing number of consumers. Furthermore, we show that large-sample optimal dynamic prices can be efficiently derived via an algorithm that only requires querying HEMS about their planned consumption schedules given different prices. We demonstrate our approach in a grid simulation powered by OpenDSS, and show that it achieves meaningful demand response without creating grid instability.Mohammad Mehrabi, Omer Karaduman, Stefan Wagerhttps://arxiv.org/abs/2409.07655</div><div class="event_time">16:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room E 3</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"> Stefan Wager (Stanford University)</div><div class="event_title">Joint talk ETH-FDS Seminar - Research Seminar on Statistics: "Optimal Mechanisms for Demand Response: An Indifference Set Approach" <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br /> 	The time at which renewable (e.g., solar or wind) energy resources produce electricity cannot generally be controlled. In many settings, consumers have some flexibility in their energy consumption needs, and there is growing interest in demand-response programs that leverage this flexibility to shift energy consumption to better match renewable production -- thus enabling more efficient utilization of these resources. We study optimal demand response in a model where consumers operate home energy management systems (HEMS) that can compute the "indifference set" of energy-consumption profiles that meet pre-specified consumer objectives, receive demand-response signals from the grid, and control consumer devices within the indifference set. For example, if a consumer asks for the indoor temperature to remain between certain upper and lower bounds, a HEMS could time use of air conditioning or heating to align with high renewable production when possible. Here, we show that while price-based mechanisms do not in general achieve optimal demand response, i.e., dynamic pricing cannot induce HEMS to choose optimal demand consumption profiles within the available indifference sets, pricing is asymptotically optimal in a mean-field limit with a growing number of consumers. Furthermore, we show that large-sample optimal dynamic prices can be efficiently derived via an algorithm that only requires querying HEMS about their planned consumption schedules given different prices. We demonstrate our approach in a grid simulation powered by OpenDSS, and show that it achieves meaningful demand response without creating grid instability. Mohammad Mehrabi, Omer Karaduman, Stefan Wager https://arxiv.org/abs/2409.07655</div><div class="event_time">16:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room E 3</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://k-os.math.ethz.ch">[K-OS] Knot Online Seminar</a></div><br /><div class="event_speaker"> Patricia Cahn (Smith College)</div><div class="event_title">Rep-Tiles <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />An n-dimensional rep-tile is a PL submanifold of &reals;<sup>n</sup> that can be decomposed into isometric re-scaled copies of itself, with non-overlapping interiors. We give a complete isotopy classification of rep-tiles in all dimensions. This is joint work with Blair, Kjuchukova, and Schwartz.</div><div class="event_time">16:15 &bull; <a class="external" href="https://u-paris.zoom.us/j/87853056962">online</a></div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/annonces/groupes-geometrie">Groupes et Géométrie </a></div><br /><div class="event_speaker"> Yash  Lodha (University of Hawaii at Manoa)</div><div class="event_title">Mini course: Orderability and groups of dynamical origin <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The study of bi-orderable groups has a long history that goes back to seminal work of Dedekind, H older and Hilbert. The study of left orderable groups has more modern origins, and the notion provides a remarkable characterization of whether a countable group admits a faithful action by orientation preserving homeomorphisms on the real line.In this mini course we will introduce and study these notions.The first lecture will be an introduction to left orderable and bi-orderable groups,and shall describe an algebraic point of view.The second lecture will feature various examples of groups of dynamical origin that naturally emerge as groups of homeomorphisms of the real line and the circle.The third lecture will describe connections with the analytic notions of second bounded cohomology, rotation numbers, stable commutator length and quasi-morphisms.The fourth lecture will focus on the space of left orders on a countable group and the Witte-Morris theorem.Throughout the mini course, I will discuss open problems and new directions of research.</div><div class="event_time">16:15 &bull; Université de Genève, Conseil Général 7-9, Room 1-15</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.math.uzh.ch/mat675.1">PDE and Mathematical Physics</a></div><br /><div class="event_speaker">Dr. Ayman Said (CNRS)</div><div class="event_title">A classification theorem for steady Euler 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 I am going to present a recent result in collaboration with Tarek Elgindi, Yupei Huang and Chujing Xie where we show that all analytic steady solutions to the Euler equations in a simply connected domain are either radial or global solution to a semi-linear elliptic equation of the \\(\\Delta \\psi= F(\\psi)\\).</div><div class="event_time">16:15 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 46</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/talks-in-financial-and-insurance-mathematics">Talks in Financial and Insurance Mathematics</a></div><br /><div class="event_speaker"> Sascha Günther (Université de Lausanne)</div><div class="event_title">Efficiently computing annuity conversion factors via feed-forward neural networks <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Many pension plans and private retirement products contain annuity factors, converting the funds at some future time into lifelong income. In general model settings like for example the Li-Lee mortality model, analytical values for the annuity factors are not available and one has to rely on numerical techniques. Their computation typically requires nested simulations as they depend on the interest rate level and the mortality tables at the time of retirement. We exploit the flexibility and efficiency of feed-forward neural networks to value the annuity factors at the time of retirement. In a numerical study, we compare our deep learning approach to (least-squares) Monte-Carlo (LSMC) which can be represented as a special case of the neural network (NN).</div><div class="event_time">17:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Friday, March 21      </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"> Hato Schmeiser (University of St. Gallen)</div><div class="event_title">Stochastic Dominance and Financial Pricing in Peer-to-Peer Insurance <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This paper studies the economic benefits of peer-to-peer insurance for pools of dependent and heterogeneous risks. We characterize the form of insurance contracts with proportional surplus sharing that is consistent with a second-order stochastic dominance requirement and financial pricing in an incomplete market setting. Moreover, conditions under which the proposed contract design generates utility benefits for all risk-averse policyholders are derived. In particular, we identify necessary second-moment conditions on the risks being pooled and establish sufficient conditions related to the policyholder’s background risk. The results provide new insights into the design and benefits of simple risk pooling solutions that require only limited information about the joint loss distribution and the policyholders’ preferences. </div><div class="event_time">10:00 &bull; EPF Lausanne, Extranef 126</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. Benjamin Stamm (University of Stuttgart)</div><div class="event_title"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">The reduced basis method for parametrized eigenvalue problems and application to quantum spin systems</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk, we present a reduced basis method for potentially large-scale parametrized eigenvalue problems. Within the reduced basis method approach, an effective low-dimensional subspace of the underlying Hilbert space is constructed in order to investigate the smallest eigenvalue of a parametrized Hamiltonian, i.e. hermitian matrix. The basis of this subspace is built from solutions of snapshots, i.e., eigenvectors corresponding to particular and well-chosen parameter values. We show how a greedy strategy to assemble the reduced basis, and thus to select the parameter points, can be implemented in conjunction with tensor formats, such as matrix-product-states (MPS) calculations using DMRG-optimization, for large-scale eigenvalue problems. We also present a new strategy to certify the discretisation error introduced by the reduced order modelling. Once the reduced basis has been obtained, observables required for the computation of quantities of interest can be computed with a computational complexity independent of the underlying Hilbert space for any parameter value. We illustrate the efficiency and accuracy of this approach for in the application of the computation of the ground-state of different (parametrized) quantum spin-chains.</div><div class="event_time">10:15 &bull; Universität Bern, Hochschulstrasse 4, 3012 Bern, Room 033 (Hauptgebäude)</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/fim/activities/nachdiplom-lectures">Nachdiplomvorlesung</a></div><br /><div class="event_speaker"> 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_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/seminar-in-numerical-analysis">Seminar in Numerical Analysis</a></div><br /><div class="event_speaker"> Zhaonan Dong (Inria Paris)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-in-numerical-analysis-zhaonan-dong-inria-paris/">A posteriori error analysis for discontinuous Galerkin on polytopic meshes</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />PDE models are often characterized by local features such as solution singularities, boundary layers, domains with complicated boundaries, and phase transitions. These unique characteristics make designing accurate numerical solutions challenging or demand substantial computational resources. One effective strategy is to develop novel numerical methods that support general meshes composed of polygonal or polyhedral elements, enabling adaptive refinement that efficiently captures local features. In this talk, we present recent results on a new a posteriori error analysis for the discontinuous Galerkin (dG) method applied to general computational meshes consisting of polygonal/polyhedral (polytopic) elements with an arbitrary number of faces. This analysis, which first appeared in the literature, generalizes known dG methods by allowing an arbitrary number of irregular hanging nodes per element. Moreover, under practical mesh assumptions, the new error estimator accommodates nearly any element shape--even with curved faces. We will also briefly discuss the a posteriori error estimator for the space-time dG method in solving the Allen-Cahn problem, as well as the hp-a posteriori error estimator for the DG method in tackling fourth-order PDEs. For further information about the seminar, please visit this webpage .</div><div class="event_time">11:00 &bull; Universität Basel, Room 05.001, Spiegelgasse 5, 4051 Basel</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.  Luca  Marannino (CNRS)</div><div class="event_title">Anticyclotomic Iwasawa theory of modular forms at inert primes via diagonal classes <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 outline an approach to the study of anticyclotomic Iwasawa theory of modular forms when the fixed prime p is inert in the relevant quadratic imaginary field. Following ideas of Castella-Do for the “p split" case, one can envisage a construction of an anticyclotomic Euler system arising from a suitable manipulation of certain Galois cohomology classes known as diagonal classes. We will report on this work in progress, trying to underline the main difficulties arising in the “p inert” setting.</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"> Ingrid Van Keilegom (KU Leuven)</div><div class="event_title">A Copula-Based Extension of the Kaplan-Meier Estimator under Dependent Censoring with Unknown Association <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This paper proposes a novel estimator of the survival function under dependent random right censoring, a situation frequently encountered in survival analysis. We model the relation between the survival time T and the censoring C by using a parametric copula, whose association parameter is not supposed to be known. Moreover, the survival time distribution is left unspecified, while the censoring time distribution is modeled parametrically. We develop su!cient conditions under which our model for (T, C) is identifiable, and propose an estimationprocedure for the distribution of the survival time T of interest. Our model and estimation procedure build further on the work on the copula-graphic estimator proposed by Zheng and Klein (1995) and Rivest and Wells (2001), which has the drawback of requiring the association parameter of the copula to be known, and on the recent work by Czado and Van Keilegom (2023), who suppose that both marginal distributions are parametric whereas we allow one margin to be unspecified. Our estimator is based on a pseudo-likelihood approach, and maintains low computational complexity. The asymptotic properties of the proposed estimator are shown. Additionally, we discuss an extension to include a cure fraction, addressing both identifiability and estimation issues. The practical performance of our method is validated through extensive simulation studies and an application to a breast cancer data set. </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">Prof. Dr. Hsian-Hua Tseng (Ohio State University)</div><div class="event_title">Gromov-Witten theory of Hilbert schemes of points on the affine plane II <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The goal of these two talks is to discuss results on equivariant Gromov-Witten invariants of Hilbert schemes of points on C^2. In the first talk, we present a summary of results in genus 0 due to Okounkov-Pandharipande. We also discuss some aspects of determining higher genus theory using Givental-Teleman reconstruction. In the second talk, we discuss recent progress on a detailed study of genus 1 theory.</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>';