Calendar of Physics Talks Vienna

Stability of the Electroweak Vacuum after the first LHC run
Speaker:José Espinosa (UA Barcelona)
Abstract:Joint Theory Seminar
Date: Tue, 13.01.2015
Time: 16:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, P.T. Chrusciel

Null canonical formulation and integrability of cylindrical gravitational waves
Speaker:A. Fuchs (Vienna)
Abstract:im Rahmen des Seminars in Geometric Analysis and Physics (GAP Seminar)
Date: Thu, 15.01.2015
Time: 11:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock, 1090 Wien
Contact:M. Bauer (Fak. Math, U.V.), V. Branding (Fak. Math, T.U.), D. Fajman (Fak. Phys, U.V.), J. Joudioux (Fak. Phys, U.V.)

Quantum clocks and quantum causality
Speaker:Caslav Brukner (Vienna)
Abstract:Quantum physics differs from classical physics in that no definite values can be attributed to observables independently of the measurement context. However, the notion of time and of causal order preserves such an objective status in the theory: all events are assumed to be ordered such that every event is either in the future, in the past or space-like separated from any other event. The possible interplay between quantum mechanics and general relativity may, however, require superseding such a paradigm. I will approach this problem in two steps. Firstly, I will consider a single "clock" - a time-evolving (internal) degree of freedom of a particle - to be in a superposition of regions of space-time with different ticking rates. While the "time as shown by the clock" is not well-defined, there is still the notion of global time. Secondly I will consider that ....
Date: Thu, 15.01.2015
Time: 14:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock, 1090 Wien
Contact:P.T. Chrusciel

Axion Dark Matter
Speaker:Georg Raffelt (MPP München)
Abstract:The physical nature of the cosmic dark matter remains perhaps the most vexing mystery of contemporary cosmology. One well-motivated particle-physics solution is provided by the hypothesis of axions, very weakly interacting and very low-mass particles, that would simultaneously explain why quantum-chromodynamics perfectly respects the symmetry between matter and anti-matter ("strong CP problem"). The theoretical motivation for axions, their cosmological role, experimental searches, and astrophysical limits will be explained and reviewed.
Date: Fri, 16.01.2015
Time: 10:30
Duration: 60 min
Location:Seminar Room, Wohllebengasse 12-14 (Academy building), ground floor
Contact:Josef Pradler

Quantum Simulation: Classical Digital versus Quantum analog
Speaker:Ulrich Schollwöck (LMU München)
Abstract:For many decades, the exact quantum dynamics of many-body quantum systems far from equilibrium has proven to be elusive for physicists. To make progress, Feynman proposed in 1982 to build "quantum simulators" where one quantum system under excellent control provides a quantum analog for another quantum system that is not understood. The first such quantum simulators have been realized in recent years due to the breathtaking progress in ultracold atomic gases in optical lattices. At the same time, progress in quantum information theory and in many-body statistical physics has provided us with quasi-exact numerical methods that allow in certain cases the simulation of that quantum dynamics on a classical digital computer. In this talk I want to give an introduction to both kinds of quantum simulation, their possibilities and inherent limitations, and show how both approaches can be underst
Date: Fri, 16.01.2015
Time: 11:00
Duration: 90 min
Location:Atominstitut, Stadionallee 2, Wien 2, Seminarraum
Contact:Jörg Schmiedmayer