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Thursday, 03.09.2015, 14.00 Uhr (WIAS-ESH)
Seminar Numerische Mathematik
Dr. G. R. Barrenechea, University of Strathclyde, UK:
Stabilising some inf-sup stable pairs on anisotropic quadrilateral meshes
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
The finite element solution of the Stokes problem is subject to the well-known inf-sup condition. This condition usually depends on the domain and the degree of the polynomial spaces used in the discretisation. Now, when anisotropic finite elements are used, this inf-sup condition usually degenerates with the aspect ratio. In this talk I will present results identifying the part of the pressure space that is responsible for this degeneration, and present a way to solve that. In the second part of the talk, this technique will be applied to some, non inf-sup stable this time, pairs of spaces for the Stokes and Oseen equations. The work presented in this talk is in collaboration with Mark Ainsworth (Brown) and Andreas Wachtel (Strathclyde).

Host
WIAS Berlin
Thursday, 03.09.2015, 16.00 Uhr (WIAS-ESH)
Forschungsseminar Mathematische Modelle der Photonik
M. Kantner, WIAS Berlin:
Modeling and numerical simulation of electrically pumped single-photon emitters
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Further Informations
Forschungsseminar ``Mathematische Modelle der Photonik''

Host
WIAS Berlin
Humboldt-Universität zu Berlin
Friday, 11.09.2015, 10.00 Uhr (WIAS-ESH)
Seminar Numerische Mathematik
Dr. T. Benacchio, Met Office, UK:
Towards scalable numerical weather and climate prediction with mixed finite element discretizations
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
The nature of atmospheric processes presents a unique set of challenges to numerical modelling, as coupled nonlinear phenomena evolve on a wide range of spatial and temporal scales extending across several orders of magnitude.. Timely and reliable forecasts require accurate simulation of transport processes together with robust handling of waves and balanced regimes, with competitive and scalable performance a key requisite on increasingly parallel architectures. Features of the nonhydrostatic compressible dynamical core in operation at the Met Office will be outlined, with particular reference to the scalability bottleneck given by the currently employed latitude-longitude grid structure. The talk will then focus on theoretical and computational aspects and open challenges of the mixed finite element numerical scheme on quasi-uniform spherical grids underpinning the next generation dynamical core.

Host
WIAS Berlin
September 17 – 18, 2015 (WIAS-ESH)
Workshop/Konferenz: Workshop on Recent Developments in Inverse Problems
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
WIAS Berlin
Wednesday, 23.09.2015, 15.15 Uhr (WIAS-ESH)
BERLINER OBERSEMINAR Nichtlineare partielle Differentialgleichungen (Langenbach-Seminar)
Dr. C. Kreisbeck, Universität Regensburg:
Homogenization of layered materials with rigid components in single-slip finite plasticity
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
hier

Further Informations
Berliner Oberseminar ``Nichtlineare Partielle Differentialgleichungen'' (Langenbach Seminar)

Host
WIAS Berlin
Humboldt-Universität zu Berlin
Thursday, 24.09.2015, 10.00 Uhr (WIAS-ESH)
Seminar Numerische Mathematik
Y. Gao, Université Paris-Sud, Frankreich:
Finite volume methods for first order stochastic conservation laws
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
We perform Monte-Carlo simulations in the one-dimensional torus for the first order Burgers equation forced by a stochastic source term with zero spatial integral. We suppose that this source term is a white noise in time, and consider various regularities in space. We apply a finite volume scheme combining the Godunov numerical flux with the Euler-Maruyama integrator in time. It turns out that the empirical mean converges to the space-average of the deterministic initial condition as $trightarrowinfty$. The empirical variance also stabilizes for large time, towards a limit which depends on the space regularity and on the intensity of the noise.
We then study a time explicit finite volume method with an upwind scheme for a conservation law driven by a multiplicative source term involving a $Q$-Wiener process. We present some a priori estimates including a weak BV estimate. After performing a time interpolation, we prove two entropy inequalities for the discrete solution and show that it converges up to a subsequence to a stochastic measure-valued entropy solution of the conservation law in the sense of Young measures.
The numerical part is joint work with E. Audusse and S. Boyaval while the convergence proof is joint work with T. Funaki and H. Weber.

Host
WIAS Berlin
October 12 – 14, 2015 (WIAS-ESH)
Workshop/Konferenz: Waves, Solitons and Turbulence in Optical Systems (WASTOS15)
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
WIAS Berlin
Thursday, 05.11.2015, 16.00 Uhr (WIAS-ESH)
Forschungsseminar Mathematische Modelle der Photonik
S. Pickartz, WIAS Berlin:
Reduced theory of interacting wave packets in nonlinear optical fibers
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Further Informations
Forschungsseminar ``Mathematische Modelle der Photonik''

Host
WIAS Berlin
Humboldt-Universität zu Berlin
Friday, 06.11.2015, 14.00 Uhr (WIAS-ESH)
Festkolloquium HCK60
Prof. Dr. A. Arnold, Technische Universität Wien, Österreich:
Entropy method for hypocoercive & non-symmetric Fokker-Planck equations with linear drift
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Further Informations
Im Rahmen des Berliner Oberseminars ``Nichtlineare Partielle Differentialgleichungen'' (Langenbach Seminars)

Host
WIAS Berlin
Humboldt-Universität zu Berlin
November 9 – 13, 2015 (WIAS-ESH)
Workshop/Konferenz: Workshop ``Direct and Inverse Problems for PDEs with Random Coefficients''
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
WIAS Berlin
November 30 – December 4, 2015 (WIAS-ESH)
Workshop/Konferenz: PDE2015
Theory and Applications of Partial Differential Equations
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
WIAS Berlin
Universität Kassel
December 7 – 9, 2015 (WIAS-ESH)
Workshop/Konferenz: 4th Annual ERC Berlin-Oxford Young Researchers Meeting on Applied Stochastic Analysis
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
European Research Council
WIAS Berlin
December 16 – 18, 2015 (WIAS-ESH)
Workshop/Konferenz: Stochastic Limit Analysis for Reacting Particle Systems
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
WIAS Berlin
February 22 – 26, 2016 (WIAS-ESH)
Workshop/Konferenz: ERC Workshop "Modeling Materials and Fluids using Variational Methods''
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
WIAS Berlin