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. 1</span>      <span style="float: right; text-align:right; width: 250px;">17.2 - 21.2.2025</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Spring Semester 2025</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, February 17      </div>      <div class="day_content">        <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="https://www.unine.ch/math/home/colloques_et_seminaires/seminaires-de-linstitut.html">Séminaire de Géométrie et Systèmes dynamiques </a></div><br /><div class="event_speaker"> Simon Vialaret (Universität Bochum and Paris-Saclay)</div><div class="event_title">Systolic inequalities in contact dynamics <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk I will give a general introduction to systolic inequalities in the context of contact geometry. A class of contact forms is said to satisfy a systolic inequality if all the associated Reeb flows admit a periodic orbit with uniformly controlled period. I will review classical examples arising in Riemannian and Finsler geometry, as well as connections with symplectic capacities and with a conjecture of Viterbo. Finally, I will state some known results about the non-existence of systolic inequalities for contact forms.</div><div class="event_time">10:00 &bull; Université de Neuchâtel, Rue Emile-Argand 11, Room B217</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="https://www.unine.ch/math/home/colloques_et_seminaires/seminaires-de-linstitut.html">Séminaire de Géométrie et Systèmes dynamiques </a></div><br /><div class="event_speaker"> Julian James Roche (Université de Genève)</div><div class="event_title">The Search for a K-theoretic Fundamental Class <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The fundamental class of a manifold is a well understood object - a certain element in the top dimension homology equivalent to a triangulation of the manifold. Its existence is pivotal on the orientability of the manifold, expressed in homological terms. These notions can then be extended to any generalised cohomology theory, such as topological K-theory. In this talk we will unravel what this implies for K-theory: first by finding the necessary and sufficient conditions for K-orientability of a smooth manifold, and then investigating what the associated fundamental class is.</div><div class="event_time">11:15 &bull; Université de Neuchâtel, Rue Emile-Argand 11, Room B217</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, February 18      </div>      <div class="day_content">        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/annonces/groupes-geometrie">Groupes et Géométrie </a></div><br /><div class="event_speaker"> David Perego (Université de Genève)</div><div class="event_title">Generalized word problem of bounded automata groups <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />The interplay between formal languages and groups, particularly through the word problem, has been extensively studied in the years. Attention has recently shifted to broader language classes, such as co-context-free and ET0L, with a conjecture stating that only virtually free groups have an ET0L word problem. For this reason, in this talk we focus on the generalized word problem, presenting results for stabilizers of infinite rays in bounded automaton groups. For eventually periodic rays, the associated languages are ET0L, but not context-free in general. Exploiting Schreier graphs and the study of their ends, we identify key obstructions to context-freeness.</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_ne"><a class="external" href="https://unine.ch">Université de Neuchâtel</a></div><div class="event_type"><a class="external" href="https://www.unine.ch/math/home/colloques_et_seminaires/seminaires-de-linstitut.html">Séminaire de Géométrie et Systèmes dynamiques </a></div><br /><div class="event_speaker"> Simon Vialaret (Universität Bochum and Paris-Saclay)</div><div class="event_title"> Systolic inequalities for S1-invariant contact forms in dimension 3 <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Following the previous talk, I will state a systolic inequality for the class of invariant contact forms on non-trivial circle bundles of dimension 3, and will discuss some application.</div><div class="event_time">13:00 &bull; Université de Neuchâtel, Rue Emile-Argand 11, Room B217</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"> Philippe Birken (University of Lund, Sweden)</div><div class="event_title">Waveform methods for partitioned dynamic coupling <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We consider coupled time dependent partial differential equations on separate domains, This can be used to model conjugate heat transfer, but also the transfer of wind stress between ocean and atmosphere, or flutter of airplanes. Our interest is in so called waveform relaxation. There, the subproblems are solved iteratively on a time window, given an approximation of the solution to the other problem. These methods open up variable time steps and time adaptivity while using separate codes for the subproblem. They can be combined with a relaxation step or Quasi-Newton acceleration.We first present a novel time adaptive Quasi-Newton waveform method. We then discuss convergence theory of this method. This is quite limited for the general case. For the simpler case of linear coupled heat equation with discontinuous coefficients, much more can be said in dependence on the material parameters, the mesh width and the time steps. Over the years, this has been approached on different levels, meaning fully discrete, semidiscrete, or fully continuous. Thereby, one has obtained both superlinear convergence results, and norm estimates. Currently, these results give an incomplete and seemingly conflicting picture. We review these results, and then fill some of the gaps.This is joint work with Niklas Kotarsky (Lund) and Martin Gander (Geneva).</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_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"> Tamas  Hausel  (IST Austria)</div><div class="event_title"> Anatomy of big algebras <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Big algebras are maximal commutative subalgebras of the Kirillov algebra attached to irreducible representations of a complex semisimple Lie group. In this talk we will visualize the anatomy of big algebras, in terms of skeletons and nerves. We show that it encodes sophisticated information of the representation, such as a ring structure on multiplicity spaces, the weight diagram and the crystal structure.</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. Marco Badran (ETH Z&uuml;rich, Switzerland)</div><div class="event_title">Harmonic maps to the circle with higher dimensional singular set <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We consider the problem of finding harmonic maps to the circle with a prescribed singular set in an arbitrary Riemannian manifold and characterise their uniqueness in terms of the "one-dimensional topology" of the ambient space. We then show how these maps can be used to define new notions of (n-2)-volume, leading to a promising approximation scheme for classical codimension 2 minimal surfaces.</div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, February 19      </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/seminaires/lie-sem/">Lie groups and moduli spaces </a></div><br /><div class="event_speaker"> François  Labourie  (Nice)</div><div class="event_title">Positivity and Surface Groups / Ghost algebra, Poisson bracket and convexity <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />“Positivity and surface groups”Positivity in a generalizsd flag manifold $M$ was introduced by Guichard and Wienhard. It generalizes both Lusztig poitivity and the geometry of the Shilov boundary. We will describe  this notion which is based on a simple « nesting » property and show how it helps defining positivity maps of the circle in $M$, as well as representation of surface groups with properties mimicking those arising as monodromies of hyperbolic structures. Based on work with Guichard, Wienhard, and then Pozzetti and Beyrer.“Ghost algebra, Poisson bracket and convexity”The moduli space of Anosov representations of a surface group in a semisimple group – an open set in the character variety – admits many more natural functions than the regular functions. We will study in particular length functions and correlation functions. Our main result is a formula that computes the Poisson bracket of those functions using some combinatorial devices called ghost polygons and ghost bracket encoded in a formal algebra called the ghost algebra related in some cases to the swapping algebra. As a consequence of our main theorem, we show that the set of those functions – length and correlation – is stable under the Poisson bracket. We give two applications: firstly in the presence of positivity we prove the convexity of length functions, generalizing a result of Kerckhoff in Teichmüller space. Based on work with Bridgeman.</div><div class="event_time">10:00 &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/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker"> Aitor Iribar López (ETH Zürich)</div><div class="event_title">Complex abelian varieties and their moduli IX <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Intersection theory on A_g and on Mumford\'s partial compactification</div><div class="event_time">13:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/tggroup/doku.php?id=fables">Séminaire "Fables Géométriques" </a></div><br /><div class="event_speaker"> Gurvan  Mével  (UNIGE)</div><div class="event_title">Floor diagrams and some tropical invariants in positive genus <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Göttche-Schroeter invariants are a rational tropical refined invariant, i.e. a polynomial counting genus 0 curves on toric surfaces, that can be computed with a floor diagrams approach. In this talk I will explain that this approach extends in any genus. This gives new invariants, related to ones simultaneously defined by Shustin and Sinichkin. I will then say few words on a quadratically enriched (and not refined !) version of this extension. </div><div class="event_time">14:00 &bull; Université de Genève, Conseil Général 7-9, Room 1-07</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/zahlentheorie/">Seminar Zahlentheorie</a></div><br /><div class="event_speaker"> Fabien Pazuki (University of Copenhagen)</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/number-theory-seminar-alina-ostafe-university-of-new-south-wales-1-1/">Title T.B.A.</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Title: Parallelogram inequality for abelian varieties and applications Abstract: Let $A$ be an abelian variety defined over a number field. A theorem of Rémond states that for any two finite subgroup schemes $G, H$, the Faltings height of the four isogenous abelian varieties $A/G, A/H, A/(G+H), A/(G\\cap H)$ are linked by an elegant inequality. The goal of the talk is to present an analogous inequality for abelian varieties defined over function fields, and discuss some applications in diophantine geometry. This is joint work with Richard Griffon and Samuel Le Fourn. Please note the unusual time and location! Spiegelgasse 1, Seminarraum 00.003</div><div class="event_time">14:15 &bull; Universität Basel</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://www.math.uzh.ch/aa/?events">Neuchatel - St.Gallen - Zurich Seminar in Coding Theory and Cryptography</a></div><br /><div class="event_speaker">Dr. Hassan Ou-azzou (Universität St.Gallen)</div><div class="event_title">Equivalence of Classes of Polycyclic and Skew Polycyclic Codes over Finite Fields <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We study the equivalence of families of polycyclic codes associated with polynomials of the form \\(x^n - a_{n-1}x^{n-1} - \\ldots - a_1x - a_0\\) over a finite field, \\(\\mathbb{F}_q,\\ q=p^s\\). We begin with the specific case of polycyclic codes associated with a trinomial \\(x^n - a_{\\ell} x^{\\ell} - a_0\\) (for some \\(0&lt; \\ell &lt;n\\)), which we refer to as \\(\\ell\\)-trinomial codes, after which we generalize our results to general polycyclic codes. We introduce an equivalence relation called \\(n\\)-equivalence, which extends the known notion of \\(n\\)-equivalence for constacyclic codes. We compute the number of \\(n\\)-equivalence classes for this relation and provide conditions under which two families of polycyclic (or \\(\\ell\\)-trinomial) codes are equivalent. In particular, we prove that when \\(\\gcd(n, n-\\ell, q-1) = 1\\), any \\(\\ell\\)-trinomial code family is equivalent to a trinomial code family associated with the polynomial \\(x^n - x^{\\ell} - 1\\). For \\(n=p^r\\), we give a complete classification of \\(p^{r-1}\\)-trinomial codes, and \\(p^{r-s}\\)-trinomial codes. Secondly, we extend our study to the case of skew polycyclic codes. Finally, we provide some examples as an application of the theory developed in this paper.</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_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://memento.epfl.ch/event/probability-and-stochastic-analysis-seminar/">Probability (and Stochastic Analysis) Seminar </a></div><br /><div class="event_speaker">  Bernoulli Instructor</div><div class="event_title">Low temperature asymptotic expansions in spin O(N) models in dimensions 3 and higher <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br /> I will review old and recent results on the problem of obtaining asymptotic series in powers of the temperature (T) around T=0 for local correlation functions of lattice spin models with continuous symmetries, using Reflection Positivity. After presenting the models and the problem, I will mostly discuss how to obtain the formal power series in a way that can be translated into a proof, and only briefly mention how to actually turn the formal procedure into a proof. If time permits, I will also mention some features of the d=2 case.Based on recent joint work with A. Giuliani, and on (less recent) work of Bricmont, Fontaine, Lebowitz, Lieb, and Spencer.</div><div class="event_time">16:15 &bull; EPF Lausanne, seminar room S. Ott</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Thursday, 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://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"> Tamas  Hausel</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://stat.ethz.ch/events/zukost">ZueKoSt: Seminar on Applied Statistics</a></div><br /><div class="event_speaker"> Rafael M. Frongillo (CU Boulder)</div><div class="event_title">Incentive problems in data science competitions, and how to fix them <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Abstract: Machine learning and data science competitions, wherein contestants submit predictions about held-out data points, are an increasingly common way to gather information and identify experts.  One of the most prominent platforms is Kaggle, which has run competitions with prizes up to 3 million USD.  The traditional mechanism for selecting the winner is simple: score each prediction on each held-out data point, and the contestant with the highest total score wins.  Perhaps surprisingly, this reasonable and popular mechanism can incentivize contestants to submit wildly inaccurate predictions.  The talk will begin with intuition for the incentive issues and what sort of strategic behavior one would expect---and when.  One takeaway is that, despite conventional wisdom, large held-out data sets do not always alleviate these incentive issues, and small ones do not necessarily suffer from them, as we confirm with formal results.  We will then discuss a new mechanism which is approximately truthful, in the sense that rational contestants will submit predictions which are close to their best guess.  If time permits, we will see how the same mechanism solves an open question for online learning from strategic experts.Bio: Rafael (Raf) Frongillo is an Associate Professor of Computer Science at the University of Colorado Boulder.  His research lies at the interface between theoretical machine learning and economics, primarily focusing on information elicitation mechanisms, which incentivize humans or algorithms to predict accurately.  Before Boulder, Raf was a postdoc at the Center for Research on Computation and Society at Harvard University and at Microsoft Research New York.  He received his PhD in Computer Science at UC Berkeley, advised by Christos Papadimitriou and supported by the NDSEG Fellowship.</div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG , Room G 19.2</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://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">Dr. Miguel Orbegozo Rodriguez (ETH Z&uuml;rich, Switzerland)</div><div class="event_title">Homogeneous braids are visually prime <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />For which link diagrams can we tell, simply with the 2-dimensional diagram information, whether the associated link is prime? Menasco showed that we can for alternating diagrams, and Cromwell, for positive braids. The latter further conjectured that the same would hold for any diagram for which Seifert\'s algorithm yields a minimal genus surface. This minimality property, if we also required that the diagram be a braid closure, is equivalent to the braid being homogeneous. Since these links are fibered, we can use open book techniques. I will present a criterion for how primeness of fibered links behaves under an operation called Murasugi sums, which we consider to be of independent interest; and explain how we can use it to prove Cromwell\'s conjecture for braid closures, i.e. for homogeneous braids. This is joint work with Peter Feller and Lukas Lewark.</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_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/kolloquium">Perlen-Kolloquium</a></div><br /><div class="event_speaker"> Marta Dujella</div><div class="event_title"><a class="external" href="https://dmi.unibas.ch/de/news-events/detail/doktoratskolloquium-mathematik-marta-dujella/">Uniformly counting points of bounded height on certain abelian varieties</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Counting points of bounded height on abelian varieties defined over number fields is a well-studied problem in arithmetic geometry. A classical result of Néron describes asymptotical behavior for this counting problem, with dependence on the Mordell-Weil rank of the abelian variety. In this talk, we\'ll present the problem of achieving uniform bounds in this setting. Particularly, we consider two special cases in which we are able to reach uniformity. In the first part, we consider the one-dimensional case, that of elliptic curves.</div><div class="event_time">16:15 &bull; Universität Basel, Hörsaal -101, Alte Universität, Rheinsprung 9</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/news-and-events/events/lecture-series/inaugural-introductory-farewell-lectures.html">Farewell Lectures</a></div><br /><div class="event_speaker">Prof. em. Dr. Richard Pink (ETH Z&uuml;rich, Switzerland)</div><div class="event_title">Living in a non-archimedean world, and other mathematical metaphors</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">        Friday, February 21      </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/tggroup/doku.php?id=fables">Séminaire "Fables Géométriques" </a></div><br /><div class="event_speaker"> Joé  Brendel (ETHZ)</div><div class="event_title">Split tori in S^2 x S^2, billiards and ball-embeddability <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk we will discuss the symplectic classification ofLagrangian tori that split as circles in S^2 x S^2. As it turns out,this classification is equivalent to playing mathematical billiards on arectangular table. This has many interesting applications, for exampleto Lagrangian packing and the topological study of the space ofLagrangians. We will focus on one application in particular, askingwhich Lagrangian tori are contained in the image of a symplectic ballembedding. There are many open questions of more general interestsurrounding this property of "ball-embeddability" of Lagrangians, whichwe will discuss at the end of the talk. This is joint work with Joontae Kim.</div><div class="event_time">14:00 &bull; Université de Genève, Conseil Général 7-9, Room 6-13</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/number-theory-seminar">Number Theory Seminar</a></div><br /><div class="event_speaker"> Francesco Naccarato (ETH Z&uuml;rich, Switzerland)</div><div class="event_title">On the arithmetic of critical values of polynomials <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let d>1 be an integer and let k be an algebraically closed field with char(k)=0 or char(k)>d. Given a polynomial f in k[x], its critical values C_f are the branching points of the induced map f: P^1 —> P^1. When suitably normalized, polynomials of degree d with given critical values can be parametrized in terms of their critical points, the roots of the derivative, yielding a covering T_d: A^{d-1} —> A^{d-1}. We briefly discuss the geometry of these coverings, giving a generalization of a classical result of Arnold. Motivated by this and by some applications, we consider two questions of arithmetical flavour: given a subfield L of k, for which subsets V of k is there a degree d polynomial f in L[x] with C_f=V, and are two such polynomials always related by a linear change of variable? We answer these questions in the case of quartics over any number field and discuss a link to the arithmetic of elliptic curves, as well as (time permitting) the case of higher degrees.</div><div class="event_time">14:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.epfl.ch/schools/sb/research/math/statistics-seminars/">Statistics Seminar </a></div><br /><div class="event_speaker"> Niels Richard  Hansen (University of Copenhagen)</div><div class="event_title">Assumption-Lean Aalen Regression <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In this talk I will introduce a new model-free measure of conditional association between a time-to-event and an exposure given additional covariates. The measure is called the Aalen Covariance Measure (ACM). It reduces to the cumulative effect in the partially additive time-to-event regression model, which encompasses the classical additive Aalen regression model. I will describe how to estimate ACM, which is a function of time, leveraging double/debiased machine learning techniques. This allows us to derive the estimator\'s asymptotic distribution, which can then be used for inference. The target, ACM, and the estimator will be compared to alternative parametric, semiparametric and assumption-lean measures of conditional association and their estimators. </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>';