var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-1"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=1"><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. 11</span>      <span style="float: right; text-align:right; width: 250px;">24.11 - 28.11.2025</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Autumn Semester 2025</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, November 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/fim/activities/nachdiplom-lectures">Nachdiplomvorlesung</a></div><br /><div class="event_speaker"> Eva Miranda (Universitat Politècnica de Catalunya)</div><div class="event_title">Singular Symplectic Manifolds</div><div class="event_time">10:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://theory.epfl.ch/seminar/">Theory and Combinatorics Seminar</a></div><br /><div class="event_speaker"> Jiechen Zhang</div><div class="event_title">Prophet Inequalities with Moment Knowledge <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We study a variant of the prophet inequality with limited information, where the decision maker only has access to the first \\(k\\) moments of each random variable, rather than their full distributions. In this work, it is proved that even with full moment knowledge (i.e., \\(k=\\infty\\)), the best possible competitive ratio is \\(\\bigTheta{1/ \\log n}\\), which we show can already be achieved with only knowledge of the first moment.Our result, in particular, implies that to obtain improved prophet inequalities, further assumptions, beyond moment knowledge, are needed. To showcase this direction, we establish improved bounds under additional distributional assumptions, such as MHR, bounded coefficient of variation, or bounded support.</div><div class="event_time">11:00 &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://math.ethz.ch/fim/activities/nachdiplom-lectures">Nachdiplomvorlesung</a></div><br /><div class="event_speaker"> Eugenia Malinnikova (Stanford University)</div><div class="event_title">Carleman estimates, unique continuation, and Landis conjecture</div><div class="event_time">13:15 &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"> Levin Maier (Universität Heidelberg)</div><div class="event_title">Hopf–Rinow Type Theorems and Periodic Geodesics on Half Lie Groups <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The geometric formulation of hydrodynamics by Arnold motivated the study of infinite-dimensional manifolds, and more precisely, half Lie groups — topological groups in which right multiplication is smooth while left multiplication is continuous. The main examples are groups of ( H^s ) or ( C^k ) diffeomorphisms of compact manifolds.In this talk, we will prove several Hopf–Rinow type theorems for right-invariant magnetic systems and certain Lagrangian systems on half Lie groups, extending the recent work of Bauer–Harms–Michor from the case of geodesic flows to this more general setting. Towards the end, we will show that on a half Lie group which is non-aspherical and equipped with a strong Riemannian metric, there always exists a contractible periodic geodesic.This is based on joint work with M. Bauer and F. Ruscelli.</div><div class="event_time">14:30 &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_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"> Paul  Dario (CY Cergy Paris Université)</div><div class="event_title">Parallel spin wave for the Villain model <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This talk will focus on the decay of correlations in the Villain model. We consider the low-temperature regime in dimensions d>3, where it is conjectured that the cosine-cosine correlation between two spins decays like the inverse of their distance to the power 2(d-2). The work of Bricmont, Fontaine, Lebowitz, Lieb, and Spencer (1982) shows that this correlation decays at least as fast as the inverse distance to the power d-2. I will present a recent result that improves this bound to an exponent of d-1, up to a logarithmic correction.The proof builds on a key insight of Fröhlich and Spencer (1982): at low temperature, a duality transformation combined with a renormalisation argument can be used to map the Villain model to a variant of the well-studied \\nabla\\phi interface model. This latter model can then be analysed precisely using the Helffer–Sjöstrand formula together with elliptic regularity estimates.Joint work with W. Wu.</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://www.eth-its.ethz.ch/activities/its-science-colloquium.html">ITS Science Colloquium</a></div><br /><div class="event_speaker"> Elon Lindenstrauss</div><div class="event_title">Time change rigidity of unipotent flows <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Suppose we have a measure preserving flow - i.e. a space, equipped with a probability measure,  evolving under continuous time in a way that preserves the probability measure.This induces a discrete time evolution on each cross section given by the return time map, that also can be shown to preserve an induced probability measure. What kind of different discrete time dynamical systems can be induced by same flow? Which non isomorphic flows can have cross section for which the return time maps provide isomorphic discrete time systems? It is not hard to see this latter question amounts to which non isomorphic flows can be made isomorphic if one makes a time change, i.e. speeds up or slow down the dynamics according to location. This is a classical subject, and there are very different systems  that are equivalent under the change. In my talk I will present joint work with Daren Wei, showing that for a certain natural class of flows - unipotent flows - there is a sharp dichotomy: there is one explicit subclass of unipotent flows that are all equivalent to each other (this class contains uncountably many non isomorphic systems) and another explicit class in which equivalence under time change can only come from an isomorphism. This work builds upon and is motivated by seminal work of Marina Ratner from the late 1970s.</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>    </div>    <div class="day">      <div class="day_title">        Tuesday, November 25      </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"> Gabriel Fazoli (Rennes)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/seminar-algebra-and-geometry-gabriel-fazoli-rennes/">A characterization of pencils of curves</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A pencil of plane curves determines a foliation on the projective plane which, generically, has exactly $d^2$ radial singularities, and apart from these singularities, the foliation is locally given by closed holomorphic 1-forms. In this talk, we will prove the converse statement: a foliation of degree $2d-2$ on the projective plane with singularities of this type, under generic conditions, is determined by a pencil of curves. In other words, every degree $d$ curve passing by the radial singularities is invariant. In order to do that, we will introduce the notion of flat partial connections and relate the existence of flat meromorphic extensions of a flat partial connections with the existence of invariant curves.</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_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"> Eva Miranda (Universitat Politècnica de Catalunya)</div><div class="event_title">Singular Symplectic Manifolds</div><div class="event_time">13:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://calendar.google.com/calendar/embed?mode=AGENDA&height=600&wkst=2&bgcolor=%23FFFFFF&src=t36it03v52cus2detrvinlgk18%40group.calendar.google.com&color=%235F6B02&ctz=Europe%2FZurich">Groups, Arithmetic and Algebraic Geometry Seminar </a></div><br /><div class="event_speaker"> Igor Shparlinksi (UNSW Sidney)</div><div class="event_title">Artin\'s conjecture on average and short character sums <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let N_a(x) denote the number of primes up to x for which the integer a is a primitive root. We showthat N_a(x) satisfies the asymptotic predicted by Artin\'s conjecture for almost all1\\le  a\\le  exp((log log x)^2). This improves on a result of Stephens (1969) which applies to themuch longer range  1 \\le  a \\le exp&#8289;(6(log&#8289; x log&#8289; log&#8289; x)^{1/2} )). A key ingredient in the proof is a new shortcharacter sum estimate over the integers, improving on  the range of a result of Garaev (2006).Joint work with Oleksiy Klurman and Joni Teräväinen.</div><div class="event_time">14:15 &bull; EPF Lausanne</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"> Lorenzo  La Porta  (University of Padova)</div><div class="event_title"> Singularities in the Ekedahl--Oort stratification <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will discuss recent results on the singularities of unionsof Ekedahl--Oort strata in the special fibres of some Shimura varieties.These results were obtained by studying the geometry of some natural period spaces in positive characteristic, the stacks of G-zips, and their relative flag spaces. I will present the main theorems, mention some applications and provide an overview of the techniques involved.This is joint work with Jean-Stefan Koskivirta and Stefan Reppen.</div><div class="event_time">15:00 &bull; <a class="external" href="fernuni.zoom.us/my/davidloeffler">UniDistance Suisse</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/seminaires/lie-sem/">Lie groups and moduli spaces </a></div><br /><div class="event_speaker"> Pavel Mnev (Notre Dame)</div><div class="event_title">Globalization of Chern-Simons theory on the moduli space of flat connectionsd <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Path integral of Chern-Simons theory on a closed 3-manifold gives a family of perturbative partition functions (effective BV actions induced on twisted de Rham cohomology) parametrized by the moduli space of flat connections. This family is horizontal with respect to the Grothendieck connection modulo a BV-exact term. I will outline how (a) this family can be extended to a nonhomogeneous form over triples (kinetic flat connection, gauge-fixing flat connection, metric), satisfying a differential quantum master equation (i.e., is annihilated by an appropriate “Gauss-Manin” flat superconnection);(b) one extract from the extended partition function above a volume form on the smooth irreducible stratum of moduli space, whose cohomology class is metric-independent, and hence yields an invariant of a framed 3-manifold.The talk is based on a joint work with Konstantin Wernli, arXiv:2510.18653 [math-ph]</div><div class="event_time">15:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/analysis-seminar">Analysis Seminar</a></div><br /><div class="event_speaker">Dr. Antoine Detaille (ETH Z&uuml;rich, Switzerland)</div><div class="event_title">About some approximation problems for Sobolev maps to manifolds <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In a striking contrast with the classical case of real-valued Sobolev functions, a Sobolev map with values into a given compact manifold N need not be approximable with smooth N-valued maps.    This observation, initially due to Schoen and Uhlenbeck (1983), gave rise to a whole area of research concerned with questions related to approximability properties of Sobolev mappings with values into a compact manifold.    In this talk, I will give a broad overview of this research direction, its history, the main problems it is concerned with, important known results, as well as some recent contributions.</div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_fr"><a class="external" href="https://www.unifr.ch">Université de Fribourg</a></div><div class="event_type"><a class="external" href="https://sites.google.com/view/agms-fribourg-seminars/home">Seminar Analysis and geometry on metric spaces</a></div><br /><div class="event_speaker"> Jonathan  Pim (University of Helsinki)</div><div class="event_title">Nodal resolution of quasiregular curves via bubble trees <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />I will discuss normal and quasinormal families of quasiregular curves, and in particular how studying the latter leads to a version of Gromov\' compactness theorem for quasiregular curves into manifolds of bounded geometry via bubbling of the domain. This bubbling process transforms the domain into a bubble tree over the original manifold and our procedure for extending quasiregular curves over bubbles requires us to pass to a more general class of mappings which are only asymptotically quasiregular. However, after the inductive bubbling process terminates, the sequence which has been extended to the bubble tree, converges locally uniformly to a true quasiregular curve on the bubble tree. On one hand, this limiting curve may be interpreted as a weak and non-unique replacement for the classical locally uniform limit of the original sequence. On the other hand, the measure it induces may be seen as a resolution of the singular parts of the limiting measure of the original sequence. As a corollary we obtain a normality criterion for families of quasiregular curves.Quasiregular curves are a class of mappings between non-equidimensional oriented Riemannian manifolds which includes both the classical quasiregular mappings and Gromov\'s pseudoholomorphic curves. They are defined with respect to a calibration i.e. a smooth closed form with unit comass. This calibration is used to define a replacement for the distortion inequality and the mapping induces a measure on its domain via the pullback of this calibration. The calibration gives, in some sense, the allowed directions for the curve, while the distortion constant controls both the curve\'s deviation from these allowed directions and the classical distortion.</div><div class="event_time">15:15 &bull; Université de Fribourg, PER23 room 0.05</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ne"><a class="external" href="https://unine.ch">Université de Neuchâtel</a></div><div class="event_type"><a class="external" href="http://www.unine.ch/math/home/colloques_et_seminaires/les-colloques-du-mardi.html">Colloque du Mardi </a></div><br /><div class="event_speaker"> Francesco Lin (Columbia University)</div><div class="event_title">Geometry and topology of vector fields in three-dimensions <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Understanding the locus at which a vector field on a manifold vanishes (or, more generally, k-vector fields are linearly dependent) is a fundamental problem in geometry and topology, dating back at least to the famous Hairy Ball theorem. In this talk, I will discuss some of the history of the problem, with a focus on three dimensions, and discuss a new proof using the Dirac equation of the following theorem of Gromov (and in fact a Riemannian refinement of it): on a closed three-manifold equipped with a volume form, there exist three-vector fields which are volume-preserving and are linearly independent at every point.</div><div class="event_time">16:00 &bull; Université de Neuchâtel, Rue Emile-Argand 11, Room B013</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">Yasaman Asgari (Universität Zürich)</div><div class="event_title">What is... temporal network? <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>&lt;span style="color: black; font-size: 12pt; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif;" data-olk-copy-source="MessageBody">Temporal networks offer a unique lens on complex systems that constantly change, where connections form, dissolve, and reappear, much like friendships in our own lives. While static networks capture a single moment, like a photograph, temporal networks reveal how structures evolve over time, shaping the dynamics that unfold on them. This perspective is crucial for questions ranging from disease spread to predicting where a PhD student may end up after graduation. In my talk, I begin with homophily, how similarities influence our social interactions, and show how random walks provide a richer, more dynamic understanding of these patterns. I then extend this to temporal networks and introduce a method for quantifying homophily across time scales, addressing a long-standing gap in the field. Throughout, I highlight the iterative nature of complex systems research: refining questions, adapting mathematical tools, scaling analyses with distributed computing, and grounding insights in empirical data, because every dataset tells its own story.&lt;/span>&lt;/p></div><div class="event_time">16:30 &bull; UZH Zentrum, Building KO2, Room F 150</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://ethz.ch/en/news-and-events/events/inaugural-farewell-introductory-lectures.html">Inaugural Lectures</a></div><br /><div class="event_speaker">Prof. Dr. Yilin Wang</div><div class="event_title">Geometry of Surfaces through the lens of Probability</div><div class="event_time">17:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG , Room F 30</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, November 26      </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"> Florian Lanz (Basel)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/studium/mathematik/doktorat/bernoullis-tafelrunde/detail/bernoullis-tafelrunde-florian-lanz-basel/">The Fractional Laplacian and Fractional Equations</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We introduce the fractional Laplacian operator (-?) s , motivating its study by illustrating its effectiveness in modelling super-diffusion. We then consider the fractional Gelfand equation, a fractional analogue of the classical Gelfand equation describing an isothermal gas sphere in gravitational equilibrium. In one spatial dimension, we establish existence and uniqueness of solutions, and discuss blow-up phenomena as well as the long-time behaviour of the associated parabolic flow. pdf_version</div><div class="event_time">12:15 &bull; Universität Basel, Seminarraum 05.001</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/mat760">Ergodic theory and dynamical systems seminar</a></div><br /><div class="event_speaker">Prof. Dr. Sebastian Van Strien (Imperial College)</div><div class="event_title">The Thurston algorithm for real entire transcendental maps <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>Thurston&rsquo;s characterisation theorem gives a necessary and sufficient condition for when a branched covering map of the sphere (for which the orbits of the branch points have finite cardinality) can be realised by a rational map. In spite of progress, an analogous result for entire maps of the complex plane seem to be not yet known. In this talk, I will discuss a somewhat different approach in the setting of real entire maps whose post-singular set is real and has finite cardinality.&lt;/p></div><div class="event_time">13:30 &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://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">Prof. Dr. Juliane Krämer (Fakultät für Informatik und Data Science, Universität Regensburg)</div><div class="event_title">On the Physical Security of Multivariate Signature Schemes <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p>Multivariate signature schemes are interesting for use cases where&nbsp;post-quantum security and short signatures are required. Currently, the most relevant multivariate signature schemes are UOV - which is already&nbsp;25 years old -, and variants of the UOV scheme. In this talk, I will&nbsp;present recent insights on the physical security of UOV-based signature&nbsp;schemes, i.e., their security with respect to side channel and fault&nbsp;attacks.&lt;/p></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"> Fernando Camacho Cadena (Strasbourg)</div><div class="event_title">Hamiltonian flows on (higher rank) Teichmüller spaces and self-intersecting curves <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />A hyperbolic structure on a surface S can be deformed by cutting along a curve c without self-intersections, twisting, and re-gluing. Such a deformation can also be seen as the Hamiltonian flow of the length function of c on the Teichmüller space of S, equipped with the Weil—Petersson symplectic form. In this talk, I will discuss Hamiltonian flows associated to length functions of self-intersecting curves, and their generalizations to higher rank Teichmüller spaces. This is partially joint work with J. Farre and A. Wienhard.</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://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">Dr. Matteo Ferrari (University of Vienna)</div><div class="event_title">Space-time variational formulations for the wave equation <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 consider space-time Galerkin discretizations of the acoustic wave equation. Unlike time-stepping methods, the time variable is treated as an additional dimension. Our goal is to design numerical schemes that are unconditionally stable, achieve optimal convergence rates, and are suitable for efficient implementation. We seek formulations that guarantee these properties under minimal assumptions on the discrete spaces, ensuring broad applicability. In particular, we aim at methods that go beyond piecewise continuous polynomials in time and include spline functions of arbitrary regularity.We compare properties, advantages, and limitations of three continuous variational formulations for the acoustic wave equation, which differ in the treatment of the temporal component:- a second-order-in-time scheme without integration by parts in time,- a first-order-in-time formulation,- a second-order-in-time scheme with integration by parts in time.We present recent results and highlight some open problems. This talk is based on joint work with I. Perugia and E. Zampa.</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://www.math.uzh.ch/aa/?events">Neuchatel - St.Gallen - Zurich Seminar in Coding Theory and Cryptography</a></div><br /><div class="event_speaker">Constantinos Vasilios Argyris Vlachos</div><div class="event_title">The Schwartz-Zippel Lemma and its Application to Reed-Muller codes <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;p class="p2">The Schwartz-Zippel Lemma is a fundamental tool, that provides a bound on the size of the zero set of multivariate polynomials.&lt;/p> &lt;p class="p2">In this talk we present a classical proof of the Schwartz-Zippel Lemma based on Gr&ouml;bner bases and elementary algebraic geometry, interpreting the lemma in terms of varieties, ideals and standard monomials.&lt;/p> &lt;p class="p2">One can use the Schwartz-Zippel Lemma to lower bounds the minimum distance of Reed-Muller codes.&nbsp;&lt;/p></div><div class="event_time">16:30 &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/talks-in-financial-and-insurance-mathematics">Talks in Financial and Insurance Mathematics</a></div><br /><div class="event_speaker">Dr. Valentin Tissot-Daguette (Bloomberg)</div><div class="event_title">Relaxed MOT and Mocking Martingales <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Martingale Optimal Transport (MOT) offers a powerful, robust framework to price and hedge illiquid derivatives. The primal formulation requires admissible models to exactly match the market’s implied volatility (IV) surface, imposing hard constraints on the marginal distributions.  However, in practice, the model’s IVs only need to fall within the observed bid-ask range. Mathematically, this translates into the model\'s marginal distributions being between the bid and ask marginals (when they exist) with respect to convex order, leading to a relaxation of  MOT.  By enlarging the set of admissible martingale couplings, Relaxed MOT generates wider, more realistic price bounds for illiquid instruments, including vanilla options whose payoffs exhibit mixed convexity. We finally introduce a weaker notion of mimicking martingales, coined mocking martingales, and extend Kellerer’s theorem to characterize their existence.Joint work with Shunan Sheng, Marcel Nutz (Columbia), and Bryan Liang (Bloomberg).</div><div class="event_time">17:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 19.1</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/seminar-on-stochastic-processes">Seminar on Stochastic Processes</a></div><br /><div class="event_speaker">Prof. Dr. Christophe Sabot (Université Claude Bernard Lyon 1)</div><div class="event_title">A random polymer approach to the weak disorder phase of the Vertex Reinforced Jump Process <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The Vertex Reinforced Jump Process (VRJP) is a continuous-time process closely related to the linearly edge reinforced random walk. The recurrence/transience of the VRJP can be caracterized by the asymptotic behavior of a positive martingale : the VRJP is recurrent when the limit is null and transient when it is positive. Besides, the L^p integrability of that martingale is related to the diffusive behavior of the VRJP. A large part of the talk will be devoted to recall some key properties of the VRJP and to explain how that martingale appears and how it can be interpreted as the partition function of a non-directed polymer in a very specific 1-dependent potential. At the end, we will show new results about the L^p integrability of the martingale, using the polymer interpretation and taking inspiration from some works of Junk on directed polymers,Based on a joint work with Q. Berger, A. Legrand and R. Poudevigne-Auboiron. </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">        Thursday, November 27      </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"> Bo\'az Klartag (The Weizmann Institute of Science)</div><div class="event_title">Isoperimetric inequalities in high-dimensional convex sets</div><div class="event_time">10:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://calendar.google.com/calendar/embed?mode=AGENDA&height=600&wkst=2&bgcolor=%23FFFFFF&src=t36it03v52cus2detrvinlgk18%40group.calendar.google.com&color=%235F6B02&ctz=Europe%2FZurich">Groups, Arithmetic and Algebraic Geometry Seminar </a></div><br /><div class="event_speaker"> Pierre-Henri Chaudouard</div><div class="event_title">Title T.B.A.</div><div class="event_time">13:15 &bull; EPF Lausanne</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/fim/activities/nachdiplom-lectures">Nachdiplomvorlesung</a></div><br /><div class="event_speaker"> Alberto Ibort (Universidad Carlos III de Madrid)</div><div class="event_title">Nachdiplom Colloquium: Witten-Floer with symmetry <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />After revisiting the approach by Witten and Floer to Morse theory, that is, the construction of a cochain complex, using inspiration from classical and quantum mechanics, whose cohomological invariants provide relevant information about the supporting spaces, we will address the problem of incorporating a symmetry group to the picture and the study of the corresponding equivariant theory.  This is part of a research program started in collaboration with E. Miranda.</div><div class="event_time">13:15 &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://www.math.uzh.ch/mat675.1">PDE and Mathematical Physics</a></div><br /><div class="event_speaker">Prof. Dr. Mahir Hadzic (University College London)</div><div class="event_title">On quantitative gravitational relaxation <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />&lt;div class="elementToProof">We prove quantitative decay rates for the linearised gravitational potential around compactly supported equilibria of the Vlasov-Poisson system featuring an attractive point mass potential at the origin.&nbsp; Such equilibria feature stably trapped particles with a stationary elliptic point of the characteristic flow. This presents a severe obstacle to any kind of dispersion. The problem is further complicated by the presence of an infinite-dimensional kernel. To handle these issues we combine tools from dynamical systems, Hamiltonian geometry, and scattering theory.&nbsp;&lt;/div> &lt;div class="elementToProof">&nbsp;&lt;/div> &lt;div class="elementToProof">Our theorem can be viewed as a first quantitative proof of (linear) gravitational Landau damping. It gives in particular the first complete treatment of linear stability of the vacuum solution around the point mass - an essential ingredient for nonlinear stability.&nbsp; Joint work with Matthew Schrecker.&lt;/div></div><div class="event_time">16:15 &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://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. Filip Lindskog (Stockholm University)</div><div class="event_title">Cost-of-capital valuation with risky assets <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Cost-of-capital valuation is a well-established approach to the valuation of liabilities and is one of the cornerstones of current regulatory frameworks for the insurance industry. Standard cost-of-capital considerations typically rely on the assumption that the required buffer capital is held in risk-less one-year bonds. The aim of this work is to analyze the effects of allowing investments of the buffer capital in risky assets, e.g. in a combination of stocks and bonds. In particular, we make precise how the decomposition of the buffer capital into contributions from policyholders and investors varies as the degree of riskiness of the investment increases, and highlight the role of limited liability in the case of heavy-tailed insurance risks. We present a combination of general theoretical results, explicit results for certain stochastic models and numerical results that emphasize the key findings.The talk is based on joint work with Hansjörg Albrecher and Hervé Zumbach, available on arXiv: arxiv:2511.00895</div><div class="event_time">17:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Friday, November 28      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/number-theory-seminar">Number Theory Seminar</a></div><br /><div class="event_speaker">Dr. Rena Chu (University of Goettingen )</div><div class="event_title">Short character sums evaluated at homogeneous polynomials <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br /> Let $p$ be a prime. Bounding short Dirichlet character sums is a classical problem in analytic number theory, and the celebrated work of Burgess provides nontrivial bounds for sums as short as $p^{1/4+\\varepsilon}$ for all $\\varepsilon>0$. In this talk, we will first survey known bounds in the original and generalized settings. Then we discuss the so-called ``Burgess method\'\' and present new results that rely on bounds on the multiplicative energy of certain sets in products of finite fields.</div><div class="event_time">14:15 &bull; Location T.B.A.</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/labs/anmath/seminars/">Seminar of Analysis </a></div><br /><div class="event_speaker"> Zhongkai Tao (IHES)</div><div class="event_title">Bogovskii-type operators for underdetermined PDE systems <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Motivated by the Einstein constraint equation in general relativity, I will talk about a way to construct solution operators to underdetermined PDE systems, generalizing the Bogovskii operator in fluid mechanics. It has optimal regularizing properties and has the advantage of being able to control the propagation of support. This leads to some interesting applications on the flexibility of initial data for the Einstein equations. This is based on joint work with Philip Isett, Yuchen Mao, and Sung-Jin Oh.</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_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"> Sebastian Sippel (Universität Leipzig)</div><div class="event_title">Understanding past climate extreme events and trends to constrain near-future climate risk <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The global mean surface temperature record—combining sea surface and near-surface air temperatures—is essential for understanding climate variability and change. Understanding of the past record is also key to constrain the uncertainty around future climate projections. In my talk, I will present a recent study (Sippel et al., 2024, doi:10.1038/s41586-024-08230-1) that aims to improve our understanding of the past record; and I will discuss implications and avenues to constrain near-future climate risk. Past temperature record: The early temperature record (before around 1950) is still uncertain due to evolving measurement methods, incomplete documentation, and sparse spatial coverage. Using independent reconstructions from land and ocean data, we find that historical ocean temperatures were likely measured too cold by about 0.26°C compared with land-based estimates, despite strong agreement in other periods. This cold anomaly is not explained by internal climate variability, and multiple lines of evidence—including climate attribution, timescale analysis, coastal observations, and palaeoclimate data—support a substantial cold bias in early ocean records. While global warming estimates since the mid-19th century remain unchanged, correcting this bias would yield a smaller early-20th-century warming trend, lower global decadal temperature variability, and closer alignment between models and observations.Constraining near-future climate risk: I will further discuss the implications of these findings for constraining near-future temperature projections. Moreover, I will present ongoing work on simulating physically plausible worst-case extreme events at the regional scale, using climate model simulations and so-called rare event simulation algorithms.</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_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"> Kimia  Nadjahi (ENS Paris)</div><div class="event_title">Optimal Transport-based Conformal Prediction <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Conformal Prediction (CP) is a principled framework for quantifying uncertainty in black-box learning models, by constructing prediction sets with finite-sample coverage guarantees. Traditional approaches rely on scalar nonconformity scores, which fail to fully exploit the geometric structure of multivariate outputs, such as in multi-output regression or multiclass classification. Recent methods addressing this limitation impose predefined convex shapes for the prediction sets, potentially misaligning with the intrinsic data geometry. We introduce a novel CP procedure handling multivariate score functions through the lens of optimal transport. Specifically, we leverage Monge-Kantorovich vector ranks and quantiles to construct prediction regions with flexible, potentially non-convex shapes, better suited to the complex uncertainty patterns encountered in multivariate learning tasks. We prove that our approach ensures finite-sample, distribution-free coverage properties, similar to typical CP methods. We then adapt our method for multi-output regression and multiclass classification, and also propose simple adjustments to generate adaptive prediction regions with asymptotic conditional coverage guarantees. Finally, we evaluate our method on practical regression and classification problems, illustrating its advantages in terms of (conditional) coverage and efficiency.This talk is based on the following paper: "Optimal Transport-based Conformal Prediction" (ICML 2025) with Gauthier Thurin (CNRS, ENS) and Claire Boyer (Université Paris-Saclay). </div><div class="event_time">15:15 &bull; EPF Lausanne, CM 1 517</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Alessandro Giacchetto (ETH Zürich)</div><div class="event_title">Refining Witten–Kontsevich <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The combinatorial description of the moduli space of curves in terms of ribbon graphs was one of the crucial ingredients in Kontsevich’s proof of Witten’s conjecture. The same model was used by Harer–Zagier and by Norbury to compute the Euler characteristic and the number of lattice points, respectively. In this talk, we will introduce the analogous combinatorial model for the moduli space of real curves: the moduli of metric Möbius graphs. Each such graph is equipped with a measure of non-orientability, a quantity interpolating between the complex and the real worlds. We then provide recursive formulas for the volumes and the lattice point counts of this moduli space, refining the results of Kontsevich and Norbury. Finally, we compute the refined Euler characteristic, thereby answering a question posed by Goulden, Harer, and Jackson 25 years ago.</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 class="day_content_item normal"><div class="event_location uni_be"><a class="external" href="https://www.unibe.ch">Universität Bern</a></div><div class="event_type"><a class="external" href="https://www.imsv.unibe.ch/research/talks/colloquia/index_eng.html">Colloquia on Probability and Statistics </a></div><br /><div class="event_speaker">Prof. Dr. Jean-Pierre Eckmann</div><div class="event_title"><a class="external" href="https://www.imsv.unibe.ch/research/talks/schedule/index_eng.html">Rolling stones reveal new structures in SO(3)</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This project started with the question whether one can construct a specially formed stone so that it rolls along a prescribed curve and its repetitions. We then discovered that for almost all given curves this is indeed possible, but, astonishingly, one needs to traverse TWO copies of the prescribed line to regain the original orientation of the stone. We finally discovered how this result is related to stochastic and Diophantine properties of rotations in SO(3) and SU(2).(This is work with Tsvi Tlusty and Yaroslav Sobolev). Y.I. Sobolev, R. Dong, T. Tlusty, J.-P. Eckmann, S. Granick, and B.A. Grzybowski, Solid-body trajectoids shaped to  roll along desired pathways, Nature,  620, 310 (2023)J.-P. Eckmann, Y.I. Sobolev, and T. Tlusty, Tumbling downhill along a given curve, Notices of the American Mathematical Society, 71 (2024)J.-P. Eckmann, T. Tlusty, Walks in Rotation Spaces Return Home When Doubled and Scaled, Physical Review Letters 135, 147201 (2025) </div><div class="event_time">16:15 &bull; Universität Bern, Sidlerstrasse 5, 3012 Bern, Room B6</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>';