TU Dortmund



Mathematisches Kolloquium

Datum Gastredner Thema Ort
Im Rahmen des Mathematischen Kolloquiums
Oberseminar Numerische Analysis und Optimierung
13.30 Uhr
Dr. Fernando Gaspoz
Universität Stuttgart
A Finite Element fully variational approach to Dirichlet boundary control


`` We discuss and analyze the a priori and a posteriori estimation and convergence for the Galerkin finite element approximation of an elliptic Dirichlet boundary control model problem governed by the Laplacian operator. The analytical setting of this problem uses controls with fractional regularity, this allows us to attack the problem in domains that are non-convex and 3 dimensional. “
M 511
Im Rahmen des Mathematischen Kolloquiums
17.00 Uhr
Dr. Frank Reidegeld
Fakultät für Mathematik, TU Dortmund
G_2-Orbifaltigkeiten mit ADE-Singularitäten Mathematikgebäude, Hörsaal E28
Im Rahmen des Mathematischen Kolloquiums
Oberseminar Analysis, Mathematische Physik, Dynamische Systeme
Konstantin Pankrashkin
University Paris-Sud
Self-adjoint operators of the type div sgn grad


Being motivated the study of negative-index metamaterials, we will discuss the definition and the spectral properties of the operators given by the differential expressions div h grad in a bounded domain U with a function h which is equal to 1 on a part of U and to a constant b<0 on the rest of U. We will see how the properties of such operators depend on the parameter b and on the geometry of U. In particular, one can have a non-empty essential spectrum. Based on a joint work with Claudio Cacciapuoti and Andrea Posilicano (University of Insubria).
M E19