Liebe Mitarbeiter des INS, im Rahmen des aktuellen Trimester-Programms im Hausdorff-Institut (Poppelsdorfer Allee 45) finden am Freitag, den 6.1.2017 ab 14:15Uhr zwei Vorträge statt. Details dazu folgen unten. Anschließend gibt es Kaffee/Tee und Kuchen. Viele Grüße, Daniel Peterseim 1) 14:15Uhr Christian Stohrer, Karlsruher Institut für Technologie "Finite Element Heterogeneous Multiscale Methods for Maxwell's Equations " Abstract: To approximate the effective behavior an electromagnetic wave propagating through a multiscale medium, we adapt the Finite Element Heterogeneous Multiscale Method to Maxwell's equations. The proposed method can be applied to time-harmonic and time dependent Maxwell's equations. In the talk we show how a priori-error estimates can be proven using the notion of T-coercivity for time-harmonic Maxwell's equations and a Strang-type lemma for the time-dependent case. 2) 15:00Uhr Michael Feischl, University of New South Wales, joint work with I. Sloan and F. Kuo "Fast random field generation with H-Matrices" Abstract: We use the H-matrix technology to compute the approximate square root of a covariance matrix in linear complexity. This allows us to generate normal and log-normal random fields on general finite point sets with optimal complexity. We derive rigorous error estimates, which show that particularly for short correlation length, this new method outperforms the standard method of truncating the Karhunen-Lo\`eve expansion. Besides getting rid of the log-factor in the complexity estimate, the method requires only mild assumptions on the covariance function and on the point set. Therefore, it might also be an alternative to circulant embedding, which is well-defined only for regular grids and stationary covariance functions. _______________________________________________ Ins-mitarbeiter mailing list Ins-mitarbeiter@ins.uni-bonn.de https://mail.ins.uni-bonn.de/mailman/listinfo/ins-mitarbeiter