D-MATH Weekly BulletinNews and Events (in particular 'Research Seminars') at D-MATH, ETH Zurichen-us
http://www.fim.math.ethz.ch/bulletin
Mon, 30 Mar 2015 16:09:56 +020060Andreas Mihatsch - Pre-Alpbach Minicourse - Special cycles on Shimura curves<h2 color="grey">FIM Minicourse</h2><h1>Pre-Alpbach Minicourse - Special cycles on Shimura curves</h1><br /><font color="grey">Speaker:</font> Andreas Mihatsch, Max-Planck-Institut für Mathematik, Bonn<br /><font color="grey">Location:</font> HG G 19.2 (ETH Zentrum)<br /><font color="grey">Start Date/Time:</font> 30 March 2015 @ 16:00<br /><br /><strong>Abstract:</strong><br />The mini-course is an introduction into the topic of the Alpbach Summer School 2015 to take place in July 2015. There special cycles on Shimura curves attached to an indefinite quaternion algebra will be studied which will serve to define the Fourier expansion of an elliptic modular form of weight 3/2. This will then be turned into an arithmetic surfaces setting which leads to the Fourier expansion of a non-holomorphic modular form of weight 3/2 with values in an arithmetic Chow group attached to the underlying arithmetic surface.http://www.math.ethz.ch/screen/info?guid=6945Mon, 23 Mar 2015 15:34:32 +0100Panos Parpas - Multiresolution Optimisation Algorithms: Theory and Applications<h2 color="grey">Optimization and Applications Seminar</h2><h1>Multiresolution Optimisation Algorithms: Theory and Applications</h1><br /><font color="grey">Speaker:</font> Dr. Panos Parpas, Imperial College London, London, United Kingdom<br /><font color="grey">Location:</font> HG G 19.1 (ETH Zentrum)<br /><font color="grey">Start Date/Time:</font> 30 March 2015 @ 16:30<br /><br /><strong>Abstract:</strong><br />Multiresolution optimisation algorithms are applicable when the underlying optimisation model can be modelled using varying levels of fidelity.<br />Typical examples include optimisation of systems governed by differential equations in computer vision and optimal control, the number of features in machine learning applications, the number of states in a Markov Decision Processes, and so on. Indeed anytime a finite dimensional optimisation model arises from an infinite dimensional model it is straightforward to define such a hierarchy of optimisation models. <br /> <br />In this talk we discuss how to take advantage of the availability of a hierarchy of models in a consistent manner. <br />We posit that when the so called approximation property does not hold then the best one can hope for is to match the complexity of the single resolution algorithm. <br />However, when additional assumptions can be made about the relationship between the coarse and fine models it is possible to improve the complexity of the optimisation algorithm. <br />We illustrate our points by developing a multiresolution proximal point algorithm for non-smooth optimisation and a multiresolution value iteration algorithm for Markov Decision Processes. We establish the worst case complexity of the proposed methods and compare them with the state-of-the-art in terms of theoretical convergence guarantees and numerical performance.http://www.math.ethz.ch/screen/info?guid=5067Tue, 17 Mar 2015 13:55:39 +0100Paul Nelson - Sketches on representations of the group of unimodular two-by-two matrices<h2 color="grey">ITS Informal Analytic Number Theory Seminar</h2><h1>Sketches on representations of the group of unimodular two-by-two matrices</h1><br /><font color="grey">Speaker:</font> Prof. Dr. Paul Nelson, ETH Zurich, Switzerland<br /><font color="grey">Location:</font> CLV B 4 (ETH Zentrum)<br /><font color="grey">Start Date/Time:</font> 31 March 2015 @ 10:15<br /><br /><strong>Abstract:</strong><br />I will attempt an idiosyncratic introduction to the representation theory of SL(2,R), with emphasis on how to heuristically understand analytic aspects (such as those arising in analytic number theory) without any actual calculation. I will do this by drawing pictures (inspired by the orbit method).<br />http://www.math.ethz.ch/screen/info?guid=6917Sat, 28 Mar 2015 10:41:04 +0100Giuseppe Mingione - Nonlinear aspects of Calderon-Zymund theory<h2 color="grey">Nachdiplomvorlesung</h2><h1>Nonlinear aspects of Calderon-Zymund theory</h1><br /><font color="grey">Speaker:</font> Prof. Dr. Giuseppe Mingione, Università degli Studi di Parma<br /><font color="grey">Location:</font> HG G 43 (ETH Zentrum)<br /><font color="grey">Start Date/Time:</font> 31 March 2015 @ 10:15<br /><br /><strong>Abstract:</strong><br />The classical Calderón-Zygmund theory deals with the optimal regularity properties of solutions to linear elliptic and parabolic equations. In particular, optimal integrability of solutions can be derived in terms of the assigned data. The classical approach in the linear case relies on the representation formulas via fundamental solutions and the analysis of the related singular integrals. On the other hand, the last years have witnessed the proof of a certain number of results leading to what can be called a nonlinear Calderon-Zygmund theory: the equations considered are indeed nonlinear and possibly degenerate. This is also intertwined with nonlinear potential theory, where pointwise estimates via linear and nonlinear potentials replace the use of fundamental solutions. The aim of the lectures is to give an overview of all these topics, in particular concentrating on more recent results concerning the possibility of deriving sharp potential estimates.http://www.math.ethz.ch/screen/info?guid=6641?31 March 2015Tue, 03 Feb 2015 13:35:07 +0100Andreas Mihatsch - Pre-Alpbach Minicourse - Special cycles on Shimura curves<h2 color="grey">FIM Minicourse</h2><h1>Pre-Alpbach Minicourse - Special cycles on Shimura curves</h1><br /><font color="grey">Speaker:</font> Andreas Mihatsch, Max-Planck-Institut für Mathematik, Bonn<br /><font color="grey">Location:</font> HG G 19.2 (ETH Zentrum)<br /><font color="grey">Start Date/Time:</font> 31 March 2015 @ 14:00<br /><br /><strong>Abstract:</strong><br />The mini-course is an introduction into the topic of the Alpbach Summer School 2015 to take place in July 2015. There special cycles on Shimura curves attached to an indefinite quaternion algebra will be studied which will serve to define the Fourier expansion of an elliptic modular form of weight 3/2. This will then be turned into an arithmetic surfaces setting which leads to the Fourier expansion of a non-holomorphic modular form of weight 3/2 with values in an arithmetic Chow group attached to the underlying arithmetic surface.http://www.math.ethz.ch/screen/info?guid=6946Mon, 23 Mar 2015 15:41:07 +0100Jeremie Szeftel - The resolution of the bounded L2 curvature conjecture in general relativity<h2 color="grey">Analysis Seminar</h2><h1> The resolution of the bounded L2 curvature conjecture in general relativity</h1><br /><font color="grey">Speaker:</font> Prof. Dr. Jeremie Szeftel, Laboratoire Jacques-Louis Lions, Université Pierre et Marie Curie<br /><font color="grey">Location:</font> HG G 43 (ETH Zentrum)<br /><font color="grey">Start Date/Time:</font> 31 March 2015 @ 15:15<br /><br /><strong>Abstract:</strong><br /> In order to control locally a space-time which satisfies the Einstein equations, what are the minimal assumptions one should make on its curvature tensor? The bounded $L^2$ curvature conjecture roughly asserts that one should only need $L^2$ bounds of the curvature tensor on a given space-like hypersurface. This conjecture has its roots in the remarkable developments of the last twenty years centered around the issue of optimal well-posedness for nonlinear wave equations. In this context, a corresponding conjecture for nonlinear wave equations cannot hold, unless the nonlinearity has a very special nonlinear structure. I will present the proof of this conjecture, which sheds light on the specific null structure of the Einstein equations. This lecture will require no specific background. <br />http://www.math.ethz.ch/screen/info?guid=6331Mon, 02 Mar 2015 21:01:32 +0100Andreas Mihatsch - Pre-Alpbach Minicourse - Special cycles on Shimura curves<h2 color="grey">FIM Minicourse</h2><h1>Pre-Alpbach Minicourse - Special cycles on Shimura curves</h1><br /><font color="grey">Speaker:</font> Andreas Mihatsch, Max-Planck-Institut für Mathematik, Bonn<br /><font color="grey">Location:</font> HG G 19.2 (ETH Zentrum)<br /><font color="grey">Start Date/Time:</font> 31 March 2015 @ 17:00<br /><br /><strong>Abstract:</strong><br />The mini-course is an introduction into the topic of the Alpbach Summer School 2015 to take place in July 2015. There special cycles on Shimura curves attached to an indefinite quaternion algebra will be studied which will serve to define the Fourier expansion of an elliptic modular form of weight 3/2. This will then be turned into an arithmetic surfaces setting which leads to the Fourier expansion of a non-holomorphic modular form of weight 3/2 with values in an arithmetic Chow group attached to the underlying arithmetic surface.http://www.math.ethz.ch/screen/info?guid=6947Mon, 23 Mar 2015 15:43:00 +0100Salvatore Stuvard - What is... a tangent cone?<h2 color="grey">Zurich Graduate Colloquium (uzh)</h2><h1>What is... a tangent cone?</h1><br /><font color="grey">Speaker:</font> Salvatore Stuvard, Universität Zürich<br /><font color="grey">Location:</font> KO2 F 150 (UZH Zentrum)<br /><font color="grey">Start Date/Time:</font> 31 March 2015 @ 17:15http://www.math.ethz.ch/screen/info?guid=6737Tue, 24 Feb 2015 17:00:09 +0100