Vorträge in der Woche 30.06.2014 bis 06.07.2014

Montag, 30.06.2014: Zeta functions and L-functions on affine Weyl groups

Ming-Hsuan Kang (NCTU, Taiwan)

Dienstag, 01.07.2014: Optimale Steuerung quasilinearer PDGs mit Hysterese

M. Lang-Batsching, TU München

Wir wollen in diesem Vortrag die optimale Steuerung der Wärmeleitungsgleichung, die mit einem Hystereseoperator gekoppelt ist, betrachten. Nach einer kurzen Motivation des Problems, wollen wir die Existenz einer Lösung des Optimalsteuerungsproblemes diskutieren. Abschließend werden wir noch auf das Problem notwendiger Optimalitätsbedingungen des Optimalsteuerungsproblemes eingehen.

Mittwoch, 02.07.2014: Morse-Homologie nach Smale und Milnor, Teil II

Marc Hake

Mittwoch, 02.07.2014: Birdtrack construction of SU(N) projection operators

Stefan Keppeler (Tübingen)

I outline a general recipe for constructing orthogonal bases for the calculation of color structures appearing in QCD for any number of partons and arbitrary N_c. The bases are constructed using hermitian gluon projectors onto irreducible subspaces invariant under SU(N_c ). Thus, each basis vector is associated with an irreducible representation of SU(N_c). The resulting multiplet bases are not only orthogonal, but also minimal for finite N_c. As a consequence, for calculations involving many colored particles, the number of basis vectors is reduced significantly compared to standard approaches employing overcomplete bases.<br> This talk is based on joint work with Malin Sjödahl (Lund).

Donnerstag, 03.07.2014: On the mass-aspect tensor of asymptotically hyperbolic manifolds

Dr. Julien Cortier (IHES/ETH)

We consider non-compact Riemannian manifolds whose geometry at infinity approaches that of the hyperbolic space. They arise naturally in General Relativity and in the AdS/CFT correspondence. A fundamental result by X. Wang and by P.T. Chrusciel and M. Herzlich is that, under appropriate decay assumptions, one can define an asymptotic invariant, reminiscent of the ADM mass for asymptotically Euclidean manifolds. After a review of the definition, the invariance property as well as "positive mass theorems", we will focus on X. Wang's definition, which relies on the trace of the mass-aspect tensor. After giving examples, we will explain a method to look for other mass-like asymptotic invariants that arise under various decay assumptions. This is joint work with Mattias Dahl and Romain Gicquaud.

Donnerstag, 03.07.2014: Non-round neckpinches in Ricci flow

Prof. James Isenberg (University of Oregon)

Freitag, 04.07.2014: Buildings and counting the infinite

Ming-Hsuan Kang (NCTU, Taiwan)