var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-24"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-22"><img src="//www2.math.ethz.ch/smsjs/images/arrow_right.png"/></a></div>    <div class="sms_title">      <span style="float: left;">SMS</span>      <span>SWISS MATHEMATICAL SOCIETY</span>      <span style="float: right;">SMG</span>    </div>    <div class="sms_info">      <span style="float: left; width: 250px;">Bulletin no. 1</span>      <span style="float: right; text-align:right; width: 250px;">16.2 - 20.2.2026</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Spring Semester 2026</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, February 16      </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"> Matteo  Russo (EPFL)</div><div class="event_title"> A Learning Perspective on Random-Order Covering Problems <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In the random-order online set cover problem, the instance with m sets and n elements is chosen in a worst-case fashion, but then the elements arrive in a uniformly random order. Can this random-order model allow us to circumvent the bound of $O(log m log n)$-competitiveness for the adversarial arrival order model? This long-standing question was recently resolved by Gupta et al. (FOCS 2021), who gave an algorithm that achieved an $O(log mn)$-competitive ratio. While their LearnOrCover was inspired by ideas in online learning (and specifically the multiplicative weights update method), the analysis proceeded by showing progress from first principles.In this work, we show a concrete connection between random-order set cover and stochastic mirror-descent/online convex optimization. In particular, we show how additive/multiplicative regret bounds for the latter translate into competitiveness for the former. Indeed, we give a clean recipe for this translation, allowing us to extend our results to covering integer programs, set multicover, and non-metric facility location in the random order model, matching (and giving simpler proofs of) the previous applications of the LearnOrCover framework.This is based on joint work with Anupam Gupta and Marco Molinaro that appeared in SOSA 2026.</div><div class="event_time">11:00 &bull; EPF Lausanne, INJ114</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"> Frederik Ravn Klausen (University of Cambridge)</div><div class="event_title">XOR trick for the Ising model and its graphical representations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Studying the Ising model using its graphical representations has been tremendously successful.These representations are coupled to each other using the uniform even subgraph, which is invariant under XOR.This trick enables simple proofs of equality of critical points between loop O(1) and Ising and exponential decay for the two-dimensional near-critical model. The scaling limit of the latter is famously conjectured to be related to the exceptional Lie Algebra E_8. Joint work with Ulrik Hansen, Jiangping Jiang and Peter Wildemann.</div><div class="event_time">16:15 &bull; Université de Genève, Conseil Général 7-9, Room 1.15</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, February 17      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/annonces/groupes-geometrie">Groupes et Géométrie </a></div><br /><div class="event_speaker"> Lasse  Rempe  (University of Manchester)</div><div class="event_title">A counterexample to Eremenko\'s conjecture <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let f be an entire function (i.e., a holomorphic self-map of the complex plane), and suppose that f is transcendental, i.e., not a polynomial. The *escaping set* of f consists of those points that tend to infinity under repeated application of f. (For example, all real numbers belong to the escaping set of the exponential map, since they tend to infinity under repeated exponentiation.) In 1989, Eremenko conjectured that every connected component of the escaping set is unbounded. Eremenko\'s conjecture has been a central problem in transcendental dynamics. Prior to our most recent work, a number of stronger versions of the conjecture had been disproved, while weaker ones had been established, and the conjecture has also been shown to hold for a number of classes of functions. I will describe recent work with David Martí-Pete and James Waterman in which we construct a counterexample to the conjecture. The talk should be accessible to a general mathematical audience, including postgraduate students. </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_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/algebraische-geometrie/">Seminar Algebra and Geometry</a></div><br /><div class="event_speaker"> Michela Artebani (Universidad de Concepción)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-algebra-and-geometry-michela-artebani-universidad-de-concepcion/">On Cox rings of Calabi-Yau hypersurfaces of smooth toric Fano varieties</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The classification of  Mori dream spaces - equivalently, normal projective varieties with finitely generated Cox ring - is closely tied to positivity properties of the anticanonical class. In particular, toric and Fano varieties provide fundamental classes of examples with finitely generated Cox rings. In contrast, Calabi-Yau varieties lie at the boundary of positivity: there is no general criterion deciding when they are Mori dream spaces, and their birational geometry (and birational automorphism groups) can be remarkably rich. In this talk we focus on Calabi--Yau varieties $X$ arising as  general anticanonical hypersurfaces of smooth toric Fano varieties $Z$. Our results are formulated in terms of primitive pairs of the anticanonical polytope of $Z$, which is a smooth reflexive polytope. We present two complementary theorems. The first result provides sufficient combinatorial conditions on primitive pairs ensuring that $X$ is a Mori dream space, and it yields an explicit presentation of the Cox ring $R(X)$ in terms of $R(Z)$  and the defining equation of $X$. The second result goes in the opposite direction: the existence of certain relations among primitive pairs forces $\\mathrm{Bir}(X)$ to be infinite, and hence $X$ cannot be a Mori dream space. The proof of the first theorem builds on the approach of Herrera-Laface-Ugaglia on Cox rings of embedded varieties, while the second generalizes ideas of Kawamata and Ottem for anticanonical hypersurfaces in products of projective spaces. As an application, we obtain a complete classification of Mori dream Calabi-Yau hypersurfaces in dimensions $2$ and $3$. In particular, for these hypersurfaces there is a sharp dichotomy:  either $R(X)$ is finitely generated  or $\\mathrm{Bir}(X)$ is infinite. This is joint work with Antonio Laface and Luca Ugaglia.</div><div class="event_time">10:30 &bull; Universität Basel, Spiegelgasse 5, Seminarraum 05.002</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/annonces/seminaire-danalyse-numerique">Séminaire d\'Analyse Numérique </a></div><br /><div class="event_speaker"> Gabriel  Wittum</div><div class="event_title">Parallel Adaptive Simulation of Processes from Science and Engineering <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Numerical simulation has become one of the major topics in Computational Science. To promote modelling and simulation of complex problems new strategies are needed allowing for the solution of large, complex model systems. Crucial issues for such strategies are reliability, efficiency, robustness, usability, and versatility.After discussing the needs of large-scale simulation we point out basic simulation strategies such as adaptivity, parallelism and multi-grid solvers. To allow adaptive, parallel computations the load balancing problem for dynamically changing grids has to be solved efficiently by fast heuristics. These strategies are combined in the simulation system UG (“Unstructured Grids”) being presented in the following.In the second part of the seminar we show the performance and efficiency of this strategy in various applications. In particular, the application and benefit of parallel adaptive multi-grid methods to modelling drug permeation through human skin is shown in detail.</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_dis"><a class="external" href="https://unidistance.ch">UniDistance Suisse</a></div><div class="event_type"><a class="external" href="https://unidistance.ch/en/mathematiques-et-informatique/recherche/number-theory/number-theory-seminar">Number Theory Seminar</a></div><br /><div class="event_speaker"> Matteo  Longo  (University of Padova)</div><div class="event_title">p-adic families of Heegner points on Shimura curves and p-adic L-functions <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Heegner points (and their higher counterparts, Heegner cycles) are powerful tools in the study of the arithmetic of elliptic curves and modular forms. The question of their variation along p-adic families of modular forms (over modular curves) and the relation with BDP p-adic L-functions has been addressed through several different approaches by many authors: B. Howard in 2007, Castella in 2020, Jetchev-Loeffler-Zerbes and  Büyükboduk-Lei in 2021. I will report on some progress and partial results on analogues of these theories in the case of modular forms over quaternionic Shimura curves (defined over the field of rational numbers). The main ingredient is the systematic use of Serre-Tate expansion on Shimura curves as a replacement of Fourier expansions of elliptic modular forms, following an old approach by A. Mori. This is a work in collaboration with P. Magrone and E. Walchek.</div><div class="event_time">15:00 &bull; <a class="external" href="https://tinyurl.com/UniDistanceNTSeminar">UniDistance Suisse, Zoom</a></div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, February 18      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/algebraische-geometrie/">Seminar Algebra and Geometry</a></div><br /><div class="event_speaker"> Antonio Laface (Universidad de Concepción)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-algebra-and-geometry-antonio-laface-universidad-de-concepcion/">On blowing up minimal toric surfaces</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In 1959, Nagata produced a counterexample to Hilbert\'s 14th problem via a linear action of a non-reductive group. The resulting non-finitely generated invariant algebra can be interpreted as the Cox ring of a blow-up of P^2 at points, and in this framework he formulated his conjecture on plane curves. More recently, in joint work with Castravet, Tevelev and Ugaglia we show that if the blow-up of certain toric surfaces at a general point has a non-polyhedral pseudoeffective cone, then the pseudoeffective cone of M_{0,n} is not polyhedral for n >= 10. These results motivate a systematic study of Cox rings of blow-ups of toric varieties at a general point. In this talk I focus on minimal toric surfaces, namely those without curves of negative self-intersection. Such surfaces are cyclic quotients of either P^2 or P^1 x P^1. For quotients of P^2, the blow-up at a general point may fail to be a Mori Dream Space, for instance when the semiample cone is not closed, or when the effective cone is not closed. In contrast, for quotients of P^1 x P^1, we prove that the blow-up at a general point is always a Mori Dream Space. This is joint work with Luca Ugaglia.</div><div class="event_time">15:00 &bull; Universität Basel, Spiegelgasse 5, Seminarraum 05.001</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Thursday, February 19      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://calendar.google.com/calendar/embed?mode=AGENDA&height=600&wkst=2&bgcolor=%23FFFFFF&src=t36it03v52cus2detrvinlgk18%40group.calendar.google.com&color=%235F6B02&ctz=Europe%2FZurich">Groups, Arithmetic and Algebraic Geometry Seminar </a></div><br /><div class="event_speaker"> David  Solomon (Institut de Mathematiques de Jussieu, Paris)</div><div class="event_title">Equiangular Lines, Heisenberg Groups and Hilbert\'s 12th Problem</div><div class="event_time">14:15 &bull; EPF Lausanne, CM 1 517</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://k-os.math.ethz.ch">[K-OS] Knot Online Seminar</a></div><br /><div class="event_speaker"> Yash Loda (Purdue University)</div><div class="event_title">A solution to the Wiegold problem on perfect groups</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/colloque">Colloque de Mathématiques </a></div><br /><div class="event_speaker"> Lasse  Rempe (Université de Manchester )</div><div class="event_title">Building surfaces from equilateral triangles <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br /> The construction of conformal maps of the earth, i.e. those that faithfully depict angles and orientations, has a long history. The most famous examples are given by stereographic projection (used since antiquity) and Mercator projection (constructed in 1569 and still used for internet maps today). One may also map a tetrahedron conformally to the sphere, taking care to specify what this means at the vertices. In 1965, cartographer L. P. Lee proposed using this classical fact as the basis for a map projection with less dramatic area distortion than the classical projections.While this has not caught on, it suggests the following mathematical question: Which orientable surfaces can be conformally represented on a collection of equilateral triangles? Equivalently, which such surfaces can be built (up to a conformal change of coordinate) by glueing together a finite or infinite collection of copies of a closed equilateral triangle? Such surfaces are called *equilaterally triangulable*. The answer in the compact case is given by a famous classical theorem of Belyi, which states that a compact Riemann surface is equilaterally triangulable if and only if it is defined over a number field. These *Belyi surfaces* - and their associated “dessins d’enfants” - have found applications across many fields of mathematics, including mathematical physics.In joint work with Chris Bishop, we give a complete answer of the same question for the case of infinitely many triangles (i.e., for non-compact Riemann surfaces). The talk should be accessible to a general mathematical audience, including postgraduate students.</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://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/talks-in-financial-and-insurance-mathematics">Talks in Financial and Insurance Mathematics</a></div><br /><div class="event_speaker">Prof. Dr. Matthias Scherer (Technical University Munich)</div><div class="event_title">Pricing Insurance Contracts with an Existing Portfolio as Background Risk <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />How should an insurer price a new contract when it wants to account for the dependence between the new risk and its existing portfolio? This talk introduces a new premium principle—the conditional indifference premium—which explicitly incorporates the insurer’s current portfolio as background risk. Unlike classical law-invariant pricing rules, this approach captures the dependence between the new risk and existing exposures, yielding prices that better reflect diversification and accumulation effects. The talk will present the theoretical foundations of the conditional indifference premium, explore its axiomatic and stochastic dominance properties, and highlight its connection to risk measures and regulatory capital. Through examples with exchangeable portfolios, we illustrate how portfolio size and dependence structure influence the marginal price of additional risks, shedding new light on the limits of diversification in insurance pricing.</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, February 20      </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.epfl.ch/labs/anmath/seminars/">Seminar of Analysis </a></div><br /><div class="event_speaker"> Renato  Velozo Ruiz	</div><div class="event_title">Phase mixing and the Vlasov equation in cosmology <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 consider the Vlasov equation on expanding isotropic homogeneous tori described by the Friedmann–Lemaître–Robertson–Walker cosmological spacetimes. For expansion rate tq, with 0 &lt; q &#8804; 1/2 (excluding some exceptional values), we show that the difference of a time-normalised spatial density with the spatial average decays with a quantitative rate depending on the regularity of the initial datum.This is joint work with Martin Taylor (Imperial College London).</div><div class="event_time">14:15 &bull; EPF Lausanne, MA B1 11</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"> Yury  Polyanskiy (MIT)</div><div class="event_title">Quantization for matrix multiplication and LLMs <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Statistical science teaches that parameters can only be learned to within a certain precision due to stochasticity of the measurement operations. Similarly, modern AI research shows that LLM\'s parameters may be perturbed without significantly affecting the end-to-end performance. Given that the primitive operation that LLM rely on is matrix multiplication, a natural basic question is to understand the tradeoffs and algorithms required for low-precision approximations for this operation. In this talk we will discuss information-theoretic bounds, metric entropy and practical algorithms (NestQuant, WaterSIC) that emerged as by-products of the theory. </div><div class="event_time">15:15 &bull; EPF Lausanne, CM 1 517</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>';