var sms = '<div id="sms_bulletin">  <div id="sms_header">  <div class="do_not_print" id="arrow_left"><a href="?next=-41"><img src="//www2.math.ethz.ch/smsjs/images/arrow_left.png"/></a></div><div class="do_not_print" id="arrow_right"><a href="?next=-39"><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. 4</span>      <span style="float: right; text-align:right; width: 250px;">9.10 - 13.10.2023</span>      <span style="text-align: center; display: block; width: 250px; margin: auto; position: relative;">Autumn Semester 2023</span>    </div>  </div>  <div></div>  <div id="sms_content">    <div class="day">      <div class="day_title">        Monday, October 9      </div>      <div class="day_content">        <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">Nihar Gargava (EPFL)</div><div class="event_title">Random Arithmetic Lattices as Sphere Packings <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In 1945, Siegel showed that the expected value of the lattice-sums of a function over all the lattices of unit covolume in an n-dimensional real vector space is equal to the integral of the function. In 2012, Venkatesh restricted the lattice-sum function to a collection of lattices that had a cyclic group of symmetries and proved a similar mean value theorem. Using this approach, new lower bounds on the most optimal sphere packing density in n dimensions were established for infinitely many n. In the talk, we will outline some analogues of Siegel\'s mean value theorem over lattices. This approach has modestly improved some of the best known lattice packing bounds in many dimensions. We will speak of some variations and related ideas. (Joint work with V. Serban, M. Viazovska)</div><div class="event_time">15:00 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room H 25</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/algebraic-geometry-and-moduli-seminar">Algebraic Geometry and Moduli Seminar</a></div><br /><div class="event_speaker">Dr. Yalong Cao (RIKEN (Japan))</div><div class="event_title">Quasimaps to quivers with potentials  <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Quivers with potentials are fundamental objects in geometric representation theory and important also in Donaldson-Thomas theory of Calabi-Yau 3-categories. In this talk, we will introduce quantum corrections to such objects by counting quasimaps from curves to the critical locus of the potential. Our construction is based on the theory of gauged linear sigma model (GLSM) and uses recent development of DT theory of CY 4-folds. Joint work with Gufang Zhao.</div><div class="event_time">15:00 &bull; ETH Zentrum, Building ITS, Room  </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"> Fabian Ziltener (ETH)</div><div class="event_title">Capacities as a complete symplectic invariant <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />This talk is about joint work with Yann Guggisberg. The main result is that the set of generalized symplectic capacities is a complete invariant for every symplectic category whose objects are of the form $(M,\\omega)$, such that $M$ is compact and 1-connected, $\\omega$ is exact, and there exists a boundary component of $M$ with negative helicity. This answers a question of Cieliebak, Hofer, Latschev, and Schlenk. It appears to be the first result concerning this question, except for results for manifolds of dimension 2, ellipsoids, and polydiscs in $\\mathbb{R}^4$.If time permits, then I will also present some answers to the following question and problem of Cieliebak, Hofer, Latschev, and Schlenk:Question: Which symplectic capacities are connectedly target-representable?Problem: Find a minimal generating set of symplectic capacities.</div><div class="event_time">15:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ge"><a class="external" href="https://unige.ch">Université de Genève</a></div><div class="event_type"><a class="external" href="https://www.unige.ch/math/mpseminar/seminar.html">Séminaire de Mathématique Physique </a></div><br /><div class="event_speaker"> Vikram Giri (ETH Zürich)</div><div class="event_title">Turbulence and Nash iteration  <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />In the phenomenological theory of turbulence, ``statistical ensembles\'\' of fluid flows that obey certain symmetries are assumed to exist from which one derives various properties of the flow. In the absence of a mathematical rigorous foundation to this theory, one can ask the basic question of whether the incompressible fluid equations allow for solutions that exhibit anomalous dissipation and intermittency, two of the basic and well-established phenomena in 3 dimensional fully-developed turbulence. In the context of the incompressible Euler equations, we will use a Nash iteration, which had its origins in the problem of isometrically embedding Riemannian manifolds, to show the existence of such ``turbulent\'\' solutions. This is joint work with Hyunju Kwon and Matthew Novack. I will try to explain the background and concepts involved and the talk should be accessible to all. </div><div class="event_time">16:15 &bull; Université de Genève, Conseil Général 7-9, Room 1-15</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://ethz.ch">ETH Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/symplectic-geometry-seminar">Symplectic Geometry Seminar</a></div><br /><div class="event_speaker"> Valentin Bosshard (ETH)</div><div class="event_title">The Lagrangian cobordism group of Weinstein manifolds <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Lagrangian cobordisms induce exact triangles in the Fukayacategory. But how many exact triangles can be recovered by Lagrangiancobordisms? One way to measure this is by comparing the Lagrangiancobordism group to the Grothendieck group of the Fukaya category. In thistalk, we discuss the setting of exact conical Lagrangian submanifolds inLiouville manifolds and compute Lagrangian cobordism groups of Weinsteinmanifolds. As an application, we get a geometric interpretation for Viterborestriction for Lagrangian cobordism groups.</div><div class="event_time">16:25 &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.math.unibe.ch/research/talks/colloquium/index_eng.html">Mathematisches Kolloquium </a></div><br /><div class="event_speaker">Dr. Sylvain Calinon (IDAP)</div><div class="event_title"><a class="external" href="https://www.math.unibe.ch/research/talks/colloquium/index_eng.html">Robot learning from few samples by exploiting the structure and geometry of data</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Today\'s developments in machine learning heavily focus on big data approaches. However, many applications in robotics require learning approaches that can rely on only few demonstrations or trials. The main challenge boils down to finding structures that can be used in a wide range of tasks, which requires us to advance on several fronts, including data structures and geometric structures.As example of data structures, I will discuss the use of tensor factorization techniques that can be used in global optimization problems to efficiently extract and compress information, while providing diverse human-guided learning capabilities (imitation and environment scaffolding). As examples of geometric structures, I will discuss the use of Riemannian geometry and geometric algebra in robotics, where prior knowledge about the physical world can be embedded within the representations of skills and associated learning algorithms.</div><div class="event_time">17:15 &bull; Universität Bern, Sidlerstrasse 5, 3012 Bern, Lecture Room B6</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Tuesday, October 10      </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"> Liran Ron (Ben-Gurion University of the Negev)</div><div class="event_title">Horofunction Boundaries of finitely generated groups <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Horofunction boundaries are a nice way to approach questions about the behavior of metric spaces at infinity and learn about their geodesics. In the case of Cayley graphs of finitely generated groups, they are also fruitful when studying group actions, algebraic properties and geometric properties (such as the growth rate of the group).In this talk we would like to introduce the relevant notions, raise questions that we try to tackle these days, and talk about recent results regarding those questions. This includes the basic definitions of horofunction boundaries of f.g. groups, examples, applications, and in particular questions about the cardinality of the boundary and the relationship with group theoretic notions.</div><div class="event_time">10:30 &bull; Université de Genève, Conseil Général 7-9, Room 1-05</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://www.unil.ch/dsa/en/home/menuinst/seminaires--evenements/research-seminars.html">Talks in Actuarial Mathematics </a></div><br /><div class="event_speaker"> Manuel Guerra (ISEG, Lisbon)</div><div class="event_speaker"> Alexandra Bugalho de Moura (ISEG, Lisbon)</div><div class="event_title">‘On the minimization of the ruin probability of both cedent and reinsurer’ ‘On randomized solutions for optimization problems’ <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Alexandra Bugalho de Moura‘On the minimization of the ruin probability of both cedent and reinsurer’Abstract: We consider the optimal reinsurance problem considering both the direct insurer and the reinsurer points of view.The two players have conflicting interests, as they both seek to absorb the highest premium proportion, while assuming the least possible risk.We consider proportional reinsurance and a game where both parties aim to minimize their ruin probabilities.A set of integro-differential equations describing their ruin probability behaviour is derived, and some preliminary numerical illustrations provided.Based on those equations, Pareto equilibrium conditions are obtained.Manuel Guerra‘On randomized solutions for optimization problems’Abstract: Randomized solutions have been introduced to optimization problems, mainly due to the fact that many nonlinear problems become convex when randomized solutions are considered.Many optimization problems in insurance and finance are not convexified by randomized solutions, but spaces of randomized solutions still have useful properties for the study of such problems. Further, randomized solutions can, in many cases, be provided with meaningful economic interpretations and can be used as a tool in model construction.</div><div class="event_time">10:30 &bull; EPF Lausanne, UniL campus, Extranef - 110</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://algebra.dmi.unibas.ch/seminar.html">Seminar Algebra and Geometry</a></div><br /><div class="event_speaker"> Fabio Bernasconi (University of Basel)</div><div class="event_title"><a class="external" href="https://algebra.dmi.unibas.ch/seminar.html">Bounding del Pezzo fibrations in positive characteristic</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Fano varieties form one of the basic building blocks of algebraic varieties predicted by the Minimal Model Program, as they appear as the generic fibres of Mori fibre spaces. In this talk, I will focus on the study of generic fibres of 3-dimensional Mori fibre spaces of relative dimension 2 in positive characteristic. These are geometrically integral del Pezzo surfaces defined over an imperfect field. Due to inseparability phenomena, these surfaces reveal to be more difficult to understand both geometrically and cohomologically. In this talk, I will report on a recent work with G.Martin where we obtain a classification of canonical del Pezzo surfaces and we prove the BAB conjecture for &#949;-klt ones.</div><div class="event_time">10:30 &bull; Universität Basel, Spiegelgasse 5, Seminarraum 05.001</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_la"><a class="external" href="https://www.epfl.ch">EPF Lausanne</a></div><div class="event_type"><a class="external" href="https://calendar.google.com/calendar/embed?mode=AGENDA&height=600&wkst=2&bgcolor=%23FFFFFF&src=t36it03v52cus2detrvinlgk18%40group.calendar.google.com&color=%235F6B02&ctz=Europe%2FZurich">Groups, Arithmetic and Algebraic Geometry Seminar </a></div><br /><div class="event_speaker"> Marta Benozzo (UCL)</div><div class="event_title">On the canonical bundle formula in positive characteristic  <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />An important problem in birational geometry is trying to relate in a meaningful way the canonical bundles of the source and the base of a fibration. The first instance of such a formula is Kodaira’s canonical bundle formula for surfaces which admit a fibration with elliptic fibres. It describes the relation between the canonical bundles in terms of the singularities of the fibres and their j-invariants. In higher dimension, we do not have an equivalent of the j-invariant, but we can still define a moduli part. Over fields of characteristic 0, positivity properties of the moduli part have been studied using variations of Hodge structures. Recently, the problem has been approached with techniques from the minimal model program. These methods can be used to prove a canonical bundle formula result in positive characteristic. </div><div class="event_time">14:15 &bull; EPF Lausanne, CM 1 113</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"> Renato Renner (ETH Zurich)</div><div class="event_title">The black hole information-loss paradox from a quantum information perspective <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Consider a black hole formed from matter in a pure state, which emits Hawking radiation. Hawking posited that the entropy of the total radiation emitted would grow monotonically, for each new radiation quanta is in a mixed state, correlated only to the inside region of the black hole. Conversely, Page argued that for an old black hole, i.e., one that has emitted more than half of its mass as radiation, the entropy of the radiation decreases because information would be lost otherwise. The discrepancy between these two predictions is sometimes called the "black hole information-loss paradox”. Recent advances in this field have revalidated Page’s assertion through gravitational path integral calculations. In my talk, I will show that the paradox, particularly the recent calculations, can be elucidated from a quantum information perspective, affording a more fine-grained understanding of the entropy concepts underlying the predictions. This work is based on the preprint “The black hole information puzzle and the quantum de Finetti theorem” with Jinzhao Wang, arXiv:2110.14653.</div><div class="event_time">15:15 &bull; Université de Genève, Section de mathématiques, 7-9 rue du Conseil-Général, Room 1-07</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Wednesday, October 11      </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. Johannes Schmitt (ETH Zürich)</div><div class="event_title">Log intersection theory: from toric varieties to moduli of curves I <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Given a smooth algebraic variety (or orbifold) X with a normalcrossings divisor D, the space X decomposes into strata describing the loci where various components of D (self-)intersect. In this series of four lectures, we will study the intersection theory of X, as well as certain birational modifications of X obtained by iteratively blowing up some of the strata. In recent years, the logarithmic Chow ring of thepair (X,D) was defined to encode the intersection theory of all suchiterated blow-ups simultaneously. This allows to perform calculationswith strict transforms of cycles on X without specifying a concretebirational model of X in which they live, and has been appliedsuccessfully in studying certain geometric cycles on moduli spaces.In the first lecture, we give an overview of the relevant definitions, a sketch of some of their applications, and a roadmap for the following talks. The second lecture talks about the case where X is a toric variety (and D its toric boundary), and explains that here the entire intersection theory is described in terms of convex geometric data (the fan Sigma of X and piecewise polynomial functions on Sigma). Then we show how the language of cone stacks and Artin fans can be used to generalize from the toric situation to arbitrary pairs (X,D). Finally, we talk about ongoing work on the logarithmic Chow ring of the moduli space of curves.</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_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"> Mike Cranston (University of Ervine)</div><div class="event_title">Erdos-Kac Theorem for the number of prime ideals <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Motivated by the Erdos-Kac Central Limit Theorem, which says that the number of primes dividing a randomly selected number from 1 to N is asymptotically normal as N goes to infinity, we use another method to sample the randomly selected integer The alternative is to select an integer n with probability proportional to 1/n^s with proportionality constant 1/\\zeta(s) where \\zeta(s) is the Riemann zeta function. Techniques were developed in joint work with T. Mountford to provide a rather easy proof of the above mentioned Central Limit Theorem. The method works as well when applied to the number of irreducible factors of a randomly (using  a zeta function) selected polynomials with coefficients in a finite field, the number of prime divisors of a randomly selected Gaussian integer, or the number of prime ideals in the factorization of a randomly selected ideal in a Dedekind domain. The talk will be based on joint works with T. Mountford, A. Peltzer and E. Hsu.Note: The Probaiblity and Stochastic Analysis semianr is usually given in two parts, separated by a break. The first part is about 30 minues explainign the result. The second part is on technical asspects.</div><div class="event_time">16:00 &bull; EPF Lausanne, Bernoulli Center</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. Théophile Chaumont-Frelet (Inria)</div><div class="event_title">Asymptotically optimal a priori and a posteriori error estimates for edge finite element discretizations of time-harmonic Maxwell\'s equations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Time-harmonic Maxwell\'s equations model the propagation ofelectromagnetic waves, and their numerical discretizationby finite elements is instrumental in a large array of applications.In the simpler setting of acoustic waves, it is known that (i) the GalerkinLagrange finite element approximation to a Helmholtz problem becomesasymptotically optimal as the mesh is refined. Similarly, (ii)asymptotically constant-free a posteriori error estimates are availablefor Helmholtz problems. In this talk, considering Nédélec finite elementdiscretizations of time-harmonic Maxwell\'s equations, I will show that(i) still holds true and propose an a posteriori error estimator providing(ii). Both results appear to be novel contributions to the existingliterature.</div><div class="event_time">16:30 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room E 1.2</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_zh"><a class="external" href="https://uzh.ch">Universit&auml;t Z&uuml;rich</a></div><div class="event_type"><a class="external" href="https://math.ethz.ch/s/seminar-on-stochastic-processes">Seminar on Stochastic Processes</a></div><br /><div class="event_speaker">Prof. Dr. Aleksandar Mijatovic (University of Warwick)</div><div class="event_title">Brownian motion with asymptotically normal reflection in unbounded domains: from transience to stability <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 quantify the asymptotic behaviour of multidimensional drifltess diffusions in domains unbounded in a single direction, with asymptotically normal reflections from the boundary. We identify the critical growth/contraction rates of the domain that separate stability, null recurrence and transience. In the stable case we prove existence and uniqueness of the invariant distribution and establish the polynomial rate of decay of its tail. We also establish matching polynomial upper and lower bounds on the rate of convergence to stationarity in total variation. All exponents are explicit in the model parameters that determine the asymptotics of the growth rate of the domain, the interior covariance, and the reflection vector field. Proofs are probabilistic, and use upper and lower tail bounds for additive functionals up to return times to compact sets, for which we develop novel sub/supermartingale criteria, applicable to general continuous semimartingales. Time permitting, I will discuss the main ideas behind the proofs in the talk. This is joint work with Miha Bresar (Warwick) and Andrew Wade (Durham).</div><div class="event_time">17:15 &bull; UZH Irchel, Winterthurerstrasse 190, Z&uuml;rich, Building Y27, Room  H12</div>        </div>      </div>    </div>    <div class="day">      <div class="day_title">        Thursday, October 12      </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"> Javier Fresán (École Polytechnique, Palaiseau)</div><div class="event_title">E-functions and geometry</div><div class="event_time">10:15 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_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"><a class="external" href="http://cermics.enpc.fr/~jourdain/">Prof. Dr. Benjamin Jourdain (CERMICS)</a></div><div class="event_title">Convexity propagation and convex ordering of one-dimensional stochastic differential equations <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />We consider driftless one-dimensional stochastic differential equations. We first recall how they propagate convexity at the level of single marginals. We show that some spatial convexity of the diffusion coefficient is needed to obtain more general convexity propagation and obtain functional convexity propagation under a slight reinforcement of this necessary condition. Such conditions are not needed for directional convexity.</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, October 13      </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"> Thomas Nagler (LMU Munich)</div><div class="event_title">Vine copula models for multivariate time series</div><div class="event_time">11:00 &bull; EPF Lausanne, UniL campus, Extranef - 110</div>        </div>        <div class="day_content_item normal"><div class="event_location uni_ba"><a class="external" href="https://unibas.ch">Universität Basel</a></div><div class="event_type"><a class="external" href="https://dmi.unibas.ch/de/forschung/mathematik/seminar-in-numerical-analysis">Seminar in Numerical Analysis</a></div><br /><div class="event_speaker"> Markus Weimar  (Julius-Maximilians-Universität Würzburg)</div><div class="event_title">Harmonic Analysis meets Applications: Wavelet-based Function Spaces and Optimal Approximations of their Embeddings <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />As a rule of thumb in approximation theory, the asymptotic speed of convergence of numerical algorithms is governed by the regularity of the objects we like to approximate. Besides classical isotropic Sobolev smoothness, in the last decades the notion of so-called dominating- mixed regularity of functions turned out to be an important concept in numerical analysis. Indeed, it naturally arises in high-dimensional real-world applications, e.g., related to the electronic Schrödinger equation. Although optimal approximation rates for embeddings within the scales of isotropic or dominating-mixed Lp-Sobolev spaces are well-understood, not that much is known for embeddings across those scales (break-of-scale embeddings).In this lecture, we first review the Fourier analytic approach towards by now well-established (Besov and Triebel-Lizorkin) scales of distribution spaces that measure either isotropic or dominating-mixed regularity. In addition, we introduce new function spaces of hybrid smoothness which are able to simultaneously capture both types of regularity at the same time. As a further generalization of the aforementioned scales, they particularly include standard Sobolev spaces on domains. On the other hand, our new spaces yield an appropri- ate framework to study break-of-scale embeddings by means of harmonic analysis. We shall present (non-)adaptive wavelet-based multiscale algorithms that approximate such embed- dings at optimal dimension-independent rates of convergence. Important special cases cover the approximation of functions having dominating-mixed Sobolev smoothness w.r.t. Lp in the norm of the (isotropic) energy space H1.The talk is based on a recent paper [1] which represents the first part of a joint work with Glenn Byrenheid (FSU Jena), Markus Hansen (PU Marburg), and Janina Hübner (RU Bochum).References:[1] G. Byrenheid, J. Hübner, and M. Weimar. Rate-optimal sparse approximation of compact break-of-scale embeddings. Appl. Comput. Harmon. Anal. 65:40–66, 2023 (arXiv:2203.10011).</div><div class="event_time">11:00 &bull; Universität Basel, Spiegelgasse 5, Seminarraum 05.001</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">Prof. Dr. William Duke (UCLA)</div><div class="event_title">Integral and rational representations of forms</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_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. Almut Veraart (Imperial College Londonn)</div><div class="event_title"><a class="external" href="https://www.imsv.unibe.ch/research/talks/colloquia/index_eng.html">Extreme event propagation using counterfactual theory and vine copulas</a> <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Understanding multivariate extreme events play a crucial role in Managing the risks of complex systems since extremes are governed by their own mechanisms. Conditional on a given variable exceeding a high threshold (e.g. traffic intensity), knowing which high-impact quantities (e.g. air pollutant levels) are the mostlikely to be extreme in the future is key. We investigate the contribution of marginal extreme events on future extreme events of related quantities. We propose an Extreme Event Propagation framework to maximise counterfactual causation probabilities between a known cause and future high-impact quantities. Extreme value theory provides a tool for modelling upper tails whilst vine copulas are flexible devices for capturing a large variety of joint extremal behaviours. We optimise for theprobabilities of causation and apply our framework to a London road traffic and air pollutants dataset. We replicate documented atmospheric mechanisms beyond linear relationships. This provides a new tool for quantifying the propagation of extremes in a large variety of applications.Joint work with Valentin Courgeau.</div><div class="event_time">15:15 &bull; Universität Bern, IMSV, Alpeneggstrasse 22, 3012 Bern, Hörraum -203</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"> Richard  Guo (University of Cambridge)</div><div class="event_title">Harnessing Extra Randomness: Replicability, Flexibility and Causality <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Many modern statistical procedures are randomized in the sense that the output is a random function of data. For example, many procedures employ data splitting, which randomly divides the dataset into disjoint parts for separate purposes. Despite their flexibility and popularity, data splitting and other constructions of randomized procedures have obvious drawbacks. First, two analyses of the same dataset may lead to different results due to the extra randomness introduced. Second, randomized procedures typically lose statistical power because the entire sample is not fully utilized.To address these drawbacks, in this talk, I will study how to properly combine the results from multiple realizations (such as through multiple data splits) of a randomized procedure. I will introduce rank-transformed subsampling as a general method for delivering large sample inference of the combined result under minimal assumptions. I will illustrate the method with three applications: (1) a “hunt-and-test” procedure for detecting cancer subtypes using high-dimensional gene expression data, (2) testing the hypothesis of no direct effect in a sequentially randomized trial and (3) calibrating cross-fit “double machine learning” confidence intervals. For these problems, our method is able to derandomize and improve power. Moreover, in contrast to existing approaches for combining p-values, our method enjoys type-I error control that asymptotically approaches the nominal level. This new development opens up the possibility of designing procedures that explicitly randomize and derandomize: extra randomness is introduced to make the problem easier before being marginalized out.This talk is based on joint work with Rajen Shah.</div><div class="event_time">15:15 &bull; EPF Lausanne, CM 1 100</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. Fatemeh Rezaee (Cambridge and ETHZ)</div><div class="event_title">Constructing smoothings of stable maps <span class="abstract-button do_not_print">abstract</span></div><div class="abstract-text" style="display: none"><strong>Abstract:</strong><br />Let X be a smooth projective variety. Define a stable map f : C &#8594; X to be eventually smoothable if there is an embedding X &#8594; PN such that (C,f) occurs as the limit of a 1-parameter family of stable maps to PN with smooth domain curves. Via an explicit deformation-theoretic construction, we produce a large class of stable maps (called stable maps with model ghosts), and show that they are eventually smoothable. This is joint work with Mohan Swaminathan.</div><div class="event_time">16:00 &bull; ETH Zentrum, R&auml;mistrasse 101, Z&uuml;rich, Building HG, Room G 43</div>        </div>      </div>    </div>  </div>  <div id="sms_footer">    address: Alessandra Naldi Windler, Departement Mathematik, HG G 51.4, ETH Zurich, Raemistrasse 101, CH-8092 Zurich<br />    email: <a href="mailto:bulletin@math.ch">bulletin@math.ch</a> | phone: +41 44 632 3684 | url: <a href="https://math.ch">https://math.ch</a>    <br /><br /><img src="//www2.math.ethz.ch/smsjs/sms_logo.gif" width="150" alt="SMS/SMG Logo" title="SMS/SMG Logo" />  </div></div>';