var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-28"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-26"><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;">19.1 - 23.1.2026</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Winter Break 2025/26</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, January 19      </div>      <div class="day_content">        <div class="day_content_item no_event">        No events scheduled today!        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, January 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.unil.ch/dsa/en/home/menuinst/seminaires--evenements/research-seminars.html">Talks in Actuarial Mathematics </a></div><br /><div class="event_speaker"> Christopher Blier-Wong (University of Toronto)</div><div class="event_title">The Laplace-Stieltjes framework for conditional mean risk sharing <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Conditional Mean Risk Sharing (CMRS) offers a transparent, economically sound mechanism for allocating aggregate losses, yet its implementation in continuous multivariate models has historically been complex since computing the allocations is analytically difficult. In this talk, we establish a unified framework for computing CMRS allocations by exploiting the joint Laplace-Stieltjes transform (LST) of a random vector of risks. We derive a fundamental identity that expresses expected allocations as diagonal partial derivatives of the joint LST, circumventing the need for complex integration over singular or intractable joint densities. This approach yields closed-form or semi-analytic solutions for a broad class of dependence structures, including matrix-exponential distributions and Archimedean copulas.</div><div class="event_time">10:30 &bull; EPF Lausanne, Extranef 126</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"> Gebhard Martin (Universität Bonn)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-algebra-and-geometry-gebhard-martin-universitaet-bonn/">The Enriques surface of minimal entropy</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Salem numbers appear naturally as dynamical degrees of isometries of hyperbolic lattices and hence in the study of entropy of surface automorphisms. The conjecturally smallest Salem number is Lehmer\'s number $\\lambda_{10}$, which can be realized by automorphisms of K3 surfaces and rational surfaces by work of McMullen. In this talk, I will explain how to generalize a result of Oguiso asserting the non-realizability of $\\lambda_{10}$ for automorphisms of Enriques surfaces over the complex numbers to odd characteristics. Then, I will describe the unique counterexample in characteristic 2. This is joint work with Giacomo Mezzedimi and Davide Veniani.</div><div class="event_time">10:30 &bull; Universität Basel, Seminarraum 00.003, Spiegelgasse 1</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.unil.ch/dsa/en/home/menuinst/seminaires--evenements/research-seminars.html">Talks in Actuarial Mathematics </a></div><br /><div class="event_speaker"> Freek Holvoet (KU Leuven, Belgium)</div><div class="event_title">A multi-view contrastive learning framework for spatial embeddings in risk modelling <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Incorporating spatial information, particularly those influenced by climate, weather, and demographic factors, is crucial for improving underwriting precision and enhancing risk management in insurance. However, spatial data are often unstructured, high-dimensional, and difficult to integrate into predictive models. Embedding methods are needed to convert spatial data into meaningful representations for modelling tasks. We propose a novel multi-view contrastive learning framework for generating spatial embeddings that combine information from multiple spatial data sources. To train the model, we construct a spatial dataset that merges satellite imagery and OpenStreetMap features across Europe. The framework aligns these spatial views with coordinate-based encodings, producing low-dimensional embeddings that capture both spatial structure and contextual similarity. Once trained, the model generates embeddings directly from latitude-longitude pairs, enabling any dataset with coordinates to be enriched with meaningful spatial features without requiring access to the original spatial inputs. In a case study on French real estate prices, we compare models trained on raw coordinates against those using our spatial embeddings as inputs. The embeddings consistently improve predictive accuracy across generalised linear, additive, and boosting models, while providing interpretable spatial effects and demonstrating transferability to unseen regions.</div><div class="event_time">11:15 &bull; EPF Lausanne, Extranef 126</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Denis Nesterov (ETH Zürich)</div><div class="event_title">Compactifications and Degenerations <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 universal pattern that appears in the compactification problem for spaces parametrizing points, maps, and vector bundles associated with a complex variety. This leads to numerous interesting correspondences, shedding light on the geometry of Hilbert schemes, Hurwitz spaces, and Gieseker moduli spaces of stable sheaves.</div><div class="event_time">13:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room E 1.1</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, January 21      </div>      <div class="day_content">        <div class="day_content_item no_event">        No events scheduled today!        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Thursday, January 22      </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/seminaire-danalyse-numerique">Séminaire d\'Analyse Numérique </a></div><br /><div class="event_speaker"> Ibrahim  Almuslimani (EPFL)</div><div class="event_title">Stabilized and Adaptive Time-Stepping Schemes in GENE-X <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We present recent developments in advanced time-stepping for GENE-X, a global, nonlinear, electromagnetic, and collisional full-f gyrokinetic code. Standard approaches such as RK4 or operator splitting can be inefficient, requiring overly small timesteps, spending more time per step, and/or introducing additional errors. To address this, we have implemented two new schemes: RK43, an adaptive Runge–Kutta scheme that dynamically adjusts the timestep based on local error estimates, and PIROCK (Partitioned Runge–Kutta–Chebyshev), which treats stiff diffusion terms appearing in the collision and neutrals operators with an explicit stabilized method while handling advection terms with standard Runge–Kutta steps. Importantly, PIROCK achieves this without relying on operator splitting, treating the full system within a unified framework and thereby requiring fewer function evaluations per timestep than splitting approaches. Preliminary tests indicate that both approaches significantly improve efficiency compared to existing schemes. We will also discuss ongoing optimization efforts and outline possible future directions for enhancing large-scale gyrokinetic simulations.</div><div class="event_time">11:00 &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://theory.epfl.ch/seminar/">Theory and Combinatorics Seminar</a></div><br /><div class="event_speaker"> Tim  Göttlicher  (Aalto University)</div><div class="event_title">A Post-Quantum Lower Bound for the Locality of Sinkless Orientation <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Sinkless orientation is a special case of the Lovász Local Lemma problem, and is one of the most important problems in the theory of locality and distributed graph algorithms. We prove a lower bound for sinkless orientation in the Online-Local model, showing that the locality is 2^&#937;(log*(n)). Since the Online-Local model is the strongest among a class of models of locality, this lower bound transfers to the round complexity of quantum distributed networks (the Quantum-Local model) and other variants of locality. To obtain these results, we develop an entirely new, self-contained technique, with the potential to be generalized to other important problems in the context of locality.</div><div class="event_time">13:00 &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://stat.ethz.ch/events/zukost">ZueKoSt: Seminar on Applied Statistics</a></div><br /><div class="event_speaker"> Stephen Senn (The University of Sheffield, The Medical University of Vienna and The University of St Andrews)</div><div class="event_title">Standard errors in representing Fisher’s views on randomisation <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />One hundred years ago, RA Fisher proposed randomisation as a solution to a problem in designing trials in agriculture[1]. However, if curiosity impels a modern statistician to look up Fisher’s anniversary paper they may be in for a shock. Randomisation is usually presented as a device for eliminating bias in treatment estimates. Fisher does not start his paper by addressing this but opens as follows with another concern:“The present position of the art of field experimentation is one of rather special interest. For more than fifteen years the attention of agriculturalists has been turned to the errors of field experiments…much ingenuity has been expended in devising plans for the proper arrangement of the plots; and not without result, for there can be little doubt that the standard of accuracy has been materially, though very irregularly, raised…an estimate of field errors derived from any particular experiment may or may not be a valid estimate, and in actual field practice is usually not a valid estimate, of the averages or differences of averages of which it is required to estimate the error.” (p503)The units in agricultural experiments are plots in a field and yields from such plots cannot be regarded as independent but instead have a complex but poorly estimable spatial correlation. Medical statisticians such as myself, who are used to dealing with patients as the unit of experimentation may underestimate the formidable difficulties that such correlation structures present for the calculation of valid standard errors. It is the valid calculation of such standard errors that form the central concern of Fisher’s 1926 paper and randomisation was proposed by him as a way of finessing the issue of the correlation structure.In this talk I shall cover various issues addressed by Fisher in his 1926 paper and argue that it is an all-too-common standard error to concentrate on the value or otherwise of randomisation in calculating point estimates. We should be much more concerned with inference as a whole, which can be approximately satisfied by thinking not only of point estimates but also of standard errors. If time permits, I shall also consider some modern trends where ignoring uncertainty seems to be leading to danger.ReferenceFisher, R. A. (1926). The arrangement of field experiments. Journal of the Ministry of Agriculture of Great Britain, 33(6),  503-513.</div><div class="event_time">15:15 &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://k-os.math.ethz.ch">[K-OS] Knot Online Seminar</a></div><br /><div class="event_speaker"> Alessio Di Prisa (Scuola Normale Superiore (Pisa))</div><div class="event_title">Every negative amphichiral knot is rationally slice <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 prove that every negative amphichiral link is rationally slice, generalizing a result due to Kawauchi in 2009. The proof relies on a systematic analysis of the action induced by the negative amphichiral map on the JSJ decomposition of the link exterior. Using the same techniques, we show that every fibered negative amphichiral knot is strongly negative amphichiral, answering a question asked by Kim and Wu in 2016 on Miyazaki knots. This is joint work with Jaewon Lee (KAIST, Daejeon) and O&#287;uz &#350;avk (METU, Ankara).</div><div class="event_time">16:15 &bull; <a class="external" href="https://u-paris.zoom.us/j/87853056962">online</a></div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Friday, January 23      </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"> Alina  Harbuzova  (MIT)</div><div class="event_title"> Computational Equivalence of Spiked Covariance and Spiked Wigner Models <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This work focuses on the computational hardness of average-case problems. While the extensive study of worst-case complexity yielded the classification of problems into equivalence classes, such a classification is largely missing in average-case complexity. We address this gap by establishing the first computational equivalence between two canonical models of high-dimensional statistics: the sparse spiked covariance and sparse spiked Wigner models. Our main contribution is the first average-case reduction that transforms the sparse spiked covariance model into the sparse spiked Wigner model. Our approach leverages a new perturbation equivariance property for Gram-Schmidt orthogonalization, enabling the removal of dependence in the noise while preserving the signal. Based on arXiv:2503.02802.</div><div class="event_time">11:00 &bull; EPF Lausanne, INJ114</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Saturday, January 24      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Sam Molcho (Roma I)</div><div class="event_title">Intesection theory of compactifications of A_g</div><div class="event_time">15:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</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>';