Vorträge in der Woche 19.05.2014 bis 25.05.2014

Montag, 19.05.2014: Solving the vibrational Schroedinger equation with a Smolyak-based collocation method that obviates the need to solve a generalised eigenvalue problem.

Prof. Dr. Tucker Carrington (Queen's University Kingston, Ontario, Canada)

Montag, 19.05.2014: Konzentrationsungleichungen für das Boolesche Modell

Fabian Gieringer (Karlsruher Institut für Technologie)

Dienstag, 20.05.2014: Decomposition of primes

Michael Herrmann

Oberseminar zu Knoten und Primzahlen

Dienstag, 20.05.2014: Periodicity of sinh-Gordon solutions

Aaron Gerding

Dienstag, 20.05.2014: Homology groups and ideal class groups

Michael Fuellbier

Oberseminar zu Knoten und Primzahlen

Mittwoch, 21.05.2014: Der Morse-Smale-Witten-Komplex und das Morse-Homologie-Theorem

Marc Hake

Donnerstag, 22.05.2014: Singularity formation for kinetic equations with cubic nonlinearities

Prof. Dr. Juan J. L. Velázquez (Hausdorff Research Institute for Mathematics Bonn)

In this talk I will discuss some recent results concerning the formation of singularities for two particular kinetic equations, namely Nordheim's equation for bosons and the Weak Turbulence kinetic equation associated to the Nonlinear Schrödinger Equation. The solutions of these equations can yield singularity formation in finite time for spatially homogeneous particle distributions. The physical significance of these singularities will be discussed. Seemingly, this singular behaviour is related to the formation of Bose-Einstein condensates. Issues like the long time asymptotics for the solutions of the Weak Turbulence Equation will be also discussed. (joint work with M. Escobedo).

Freitag, 23.05.2014: My observations on how physicists use QED

Prof. Jan Derezinski (Warschau)

I will start with a short story, hopefully entertaining. Then I will discuss the general philosophy of precision computations of Lambshifts using QED, based in particular on the works of Shabaev and Pachucki. I will explain two kinds of effective Hamiltonians. Then I will discuss the formalism of time-ordered and 2-times Green's functions. Finally, if there is still time, I will say about the structure of QED and possible perturbative approaches, which are relevant for the bound state computations.

Freitag, 23.05.2014: On the topology of black holes and beyond

Prof. Greg Galloway (University of Miami)

In recent years there has been a great deal of interest in black holes in higher dimensional gravity. This, in particular, has led to questions about the topology of black holes in higher dimensions. In this talk we review Hawking's classical theorem on the topology of black holes in 3+1 dimensions (and its connection to black hole uniqueness) and present a generalization of it to higher dimensions. The latter is a geometric result which places restrictions on the topology of black holes in higher dimensions. We shall also discuss recent work on the topology of space exterior to a black hole. This is closely connected to the Principle of Topological Censorship, which roughly asserts that the topology of the region outside of all black holes (and white holes) should be simple. All of the results to be discussed rely on recent developments in the theory of marginally outer trapped surfaces, which are natural spacetime analogues of minimal surfaces in Riemannian geometry. This talk is based primarily on joint work with Rick Schoen and with Michael Eichmair and Dan Pollack.