Forschungsseminar Mathematische Statistik I. Castillo, Université Pierre et Marie Curie, Paris/Frankreich:
Some results on frequentist analysis of Bayesian posterior distributions more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Further Informations
Forschungsseminar ``Mathematische Statistik''
Host
WIAS Berlin Humboldt-Universität zu Berlin Universität Potsdam
Thursday, 23.05.2013, 16.15 Uhr (WIAS-ESH)
Forschungsseminar Mathematische Modelle der Photonik Dr. M. Radziunas, WIAS Berlin:
Modeling, simulations and analysis of beam quality improvement in broad area semiconductor devices more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Host
Humboldt-Universität zu Berlin WIAS Berlin
Friday, 24.05.2013, 10.30 Uhr (WIAS-ESH)
Seminar Numerische Mathematik Prof. H.-J. Starkloff, Westsächsische Hochschule Zwickau:
On some questions related to generalized polynomial chaos expansions more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
Generalized polynomial chaos expansions are series expansions of random variables or random functions using orthogonal polynomials in certain basic random variables. They are a versatile tool for efficiently working with stochastic quantities. So, recently they are widely used for the investigation of stochastic models, for uncertainty quantification methods or stochastic simulation purposes. In particular, recent approaches for the solution of ordinary or partial differential equations with random parameters often use certain versions of generalized polynomial chaos expansions. In the talk basic definitions and properties of generalized polynomial chaos expansions are presented. Furthermore some problems are considered which are related to convergence properties or algebraic transformations of generalized polynomial chaos expansions. The talk is based on joint work with A. Mugler (BTU Cottbus) and O. Ernst and B. Sprungk (TU Chemnitz).
Host
WIAS Berlin
Monday, 27.05.2013, 17.00 Uhr (FUB-031)
Oberseminar Numerische Mathematik/Scientific Computing Prof. A. Mahalov, Arizona State University, USA:
Stochastict three-dimensional rotating Navier-Stokes equations: Averaging, convergence and regularity more ...Location Freie Universität Berlin, Arnimallee 6, 14195 Berlin, Erdgeschoss, Raum: 031
Abstract
We consider stochastic three-dimensional rotating Navier-Stokes equations and prove averaging theorems for stochastic problems in the case of strong rotation. Regularity results are established by bootstrapping from global regularity of the limit stochastic equations and convergence theorems. The energy injected in the system by the noise is large, the initial condition has large energy, and the regularization time horizon is long. Regularization is the consequence of a precise mechanism of relevant three-dimensional nonlinear dynamics. We establish multiscale averaging and convergence theorems for the stochastic dynamics. References F. Flandoli and A. Mahalov, Stochastic 3D Rotating Navier-Stokes equations: averaging, convergence and regularity, Archive for Rational Mechanics and Analysis, 205, Issue 1 (2012), p. 195?237.
Abstract
I will present recent quantitative results for the stochastic homogenization of linear elliptic equations with random coefficients in a discrete setting. Classical qualitative homogenization theory states that on large length scales the random coefficients can be replaced by homogenized coefficients that are deterministic and constant in space. The homogenized coefficients are characterized by a formula that involves the solution to the so called "corrector problem". In contrast to periodic homogenization, in the stochastic setting the corrector problem is a highly degenerate elliptic equation on a probability space. In this talk I will explain how to obtain various optimal estimates on the corrector, on approximations of the homogenized coefficients and on the homogenization error based on a quantification of ergodicity that in particular covers the case of independent and identically distributed coefficients. The approach is mainly based on elliptic and parabolic regularity theory combined with some elements of statistical mechanics and probability theory. The talk is based on joint work with A. Gloria (Université Libre de Bruxelles) and F. Otto (MPI Leipzig).
Host
FU, ZIB, WIAS, HU, TU, Uni Potsdam
Tuesday, 28.05.2013, 14.00 Uhr (WIAS-ESH)
Seminar Partielle Differentialgleichungen V. Kapoor, Universität Rostock, Institut für Physik:
Exact exchange-correlation potentials for worst case-TDDFT scenarios more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Further Informations
Seminar Partielle Differentialgleichungen
Further Informations
Seminar ``Modern Methods in Applied Stochastics and Nonparametric Statistics''
Host
WIAS Berlin
Tuesday, 28.05.2013, 15.15 Uhr (FU Berlin)
Oberseminar Nonlinear Dynamics H. Ruan, Universität Hamburg:
A degree theory for synchrony-breaking bifurcations in coupled cell systems more ...Location Freie Universität Berlin, Arnimallee 3, 14195 Berlin, Hinterhaus, Raum 130
Abstract
A network is a graphical entity consisting of nodes and links between the nodes. In the theory of coupled cell systems, nodes of the network are interpreted as individual dynamical systems whose mutual interactions are described by the coupling structure of the network. One important and most studied collective dynamics on networks is the synchronization: a set of cells is said to be synchronized, if their individual dynamics coincide over time. Fully synchronized states where all cells are in synchrony, are rare instances. The more common phenomenon is partial synchronization where communities or clusters of cells are synchronized. A synchrony-breaking bifurcation refers to a local bifurcation, where a fully synchronous equilibrium loses its stability and bifurcates to states of less synchrony. In this talk, we introduce a lattice degree which can be used to study synchrony-breaking bifurcations, both of steady states and of oscillating states, and to predict the existence of these bifurcating branches, together with their multiplicity, symmetry and synchrony types.
Host
WIAS Berlin Freie Universität Berlin
Wednesday, 29.05.2013, 10.00 Uhr (WIAS-ESH)
Professor L. Horvath, University of Utah, USA:
Change point detection: Models and approaches more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Host
WIAS Berlin Humboldt-Universität zu Berlin Universität Potsdam
Abstract
In the past 15 years, the theory of Optimal Transport has led to significant progress in the analysis and geometry of metric measure spaces. Originally, the theory seemed to be restricted to continuous spaces, but in recent years, it was realised that ideas from Optimal Transport can be adapted to a much wider setting, with applications to discrete Markov chains and quantum evolution equations. I will present a survey of these developments.
Further Informations
Berliner Oberseminar ``Nichtlineare Partielle Differentialgleichungen'' (Langenbach Seminar)
Abstract
In this talk we describe the spectral properties of selfadjoint Schrödinger operators on unbounded domains with an associated Dirichlet-to-Neumann map. In particular, a characterization of the isolated and embedded eigenvalues, the corresponding eigenspaces, as well as the continuous and absolutely continuous spectrum in terms of the limiting behaviour of the Dirichlet-to-Neumann map is obtained. Furthermore, a sufficient criterion for the absence of singular continuous spectrum is provided. The results are natural multidimensional analogues of classical facts from singular Sturm-Liouville theory.
Further Informations
Berliner Oberseminar ``Nichtlineare Partielle Differentialgleichungen'' (Langenbach Seminar)
Host
WIAS Berlin Humboldt-Universität zu Berlin
Monday, 03.06.2013, 14.00 Uhr (WIAS-ESH)
INSTITUTSKOLLOQUIUM Dr. R. Scholz, Technische Universität Dresden, Institut für Angewandte Photophysik (IAPP):
Optoelektronische Bauelemente aus organischen Halbleitern: Simulation von spektroskopischen Eigenschaften und elektronischem Transport more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Further Informations
Institutskolloquium
Host
WIAS Berlin
Tuesday, 04.06.2013, 10.15 Uhr (WIAS-406)
Seminar Nichtlineare Optimierung und Inverse Probleme Dr. O. Pajonk, SPT Group GmbH, Hamburg:
A sampling-free method for linear Bayesian updating with application to spectral representations more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Weierstraß-Hörsaal (Raum: 406)
Abstract
We study the local energy dissipation in gradient-like nonlinear partial differential equations on unbounded domains. Our basic assumption, which happens to be satisfied in many classical examples, is a pointwise upper bound on the energy flux in terms of the energy dissipation rate. Under this hypothesis, we derive a simple and general bound on the integrated energy flux which implies that, in low space dimensions, our ``extended dissipative system'' has a gradient-like dynamics in a suitable averaged sense. In particular, we can estimate the time spent by any trajectory outside a neighborhood of the set of equilibria. As an application, we study the long-time behavior of solutions to the two-dimensional Navier-Stokes equation in an infinite cylinder. This talk is based on a collaboration with S. Slijepcevic (Zagreb, Croatia).
Further Informations
Berliner Oberseminar ``Nichtlineare Partielle Differentialgleichungen'' (Langenbach Seminar)
Host
WIAS Berlin Humboldt-Universität zu Berlin
Thursday, 27.06.2013, 14.00 Uhr (WIAS-ESH)
Seminar Numerische Mathematik S. Moore, RICAM, Austrian:
Discontinuous Galerkin isogeometric analysis for elliptic PDEs on manifolds more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
Isogeometric analysis uses the same class of basis functions for both, representing the geometry of the computational domain and approximating the solution. In practical applications, geometrical patches are used in order to get flexibility in the geometrical representation. This patch representation corresponds to a domain decomposition. In this talk, we will present a Discontinuous Galerkin (DG) Method that allows for discontinuities only along the subdomain (patch) boundaries. The required smoothness is obtained by the DG terms associated with the boundary of the subdomains. The construction and corresponding discretization error analysis of such DG scheme will be presented for Elliptic PDEs living in plane domains as well as on open and closed surfaces. This is a joint talk with Ulrich Langer (RICAM, Linz, Austria).
Host
WIAS Berlin
Thursday, 04.07.2013, 16.15 Uhr (WIAS-ESH)
Forschungsseminar Mathematische Modelle der Photonik R. Arkhipov, WIAS Berlin:
Modelling, simulations and analysis of mode-locked semiconductor lasers with external periodic forcing more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Seminar Materialmodellierung Dr. Ch. Zanini, Politechnic University of Turin, Italy:
First order approximations of finite dimensional gradient flows more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Raum: 405/406
Further Informations
WIAS-Materialmodellierungsseminar
Further Informations
Berliner Oberseminar ``Nichtlineare Partielle Differentialgleichungen'' (Langenbach Seminar)
Host
WIAS Berlin Humboldt-Universität zu Berlin
Thursday, 11.07.2013, 16.15 Uhr (WIAS-ESH)
Forschungsseminar Mathematische Modelle der Photonik Dr. U. Bandelow, WIAS Berlin:
Solitons on a background, rogue waves, and classical soliton solutions of the Sasa-Satsuma equation more ...Location Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal
Abstract
The workshop will focus on the methods and results for evolution problems driven by functionals and applications. Emphasis will be given to gradient flows for free energy or entropy as well as to generalized gradient and rate-independent systems and dissipative Hamiltonian systems, also in a multiscale setting. The issue of the variational approximation of evolution, possibly in the form of suitable evolutionary Gamma-convergence notions, will be also covered. The many applications of this wide range of techniques may include thermomechanical and materials modeling, stochastic models, multi- particle systems, transition from discrete to continuum, quantum mechanics, and reaction-diffusion systems.
The list of confirmed speakers include:
Andrea Braides, Rome, José Carrillo, London, Eduard Feireisl, Prague, Michael Herrmann, Saarbrück en, Ansgar Jüngel, Vienna, Matthias Liero, Berlin, Peter Markowich, Cambridge/Vienna, Daniel Matthes, Munich, Maria Giovanna Mora, Pavia, Elisabetta Rocca, Milan, Riccarda Rossi, Brescia, Giuseppe Savaré, Pavia, André Schlichting, Bonn, Florian Theil, Warwick, Maria Westdickenberg, Aachen, Johannes Zimmer, Bath.
Additionally, proposals for contributed talks and posters will be welcome before June 22, 2013 at the conference email eedsa13@wias-berlin.de
Please find a pdf announcement of the workshop here.
