
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, ErwinSchrödingerHörsaal, 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 spacelike 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 timeevolving (internal) degree of freedom of a particle  to be in a superposition of regions of spacetime with different ticking rates. While the "time as shown by the clock" is not welldefined, 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 
Speaker:  Georg Raffelt (MPP München) 
Abstract:  The physical nature of the cosmic dark matter remains perhaps the most vexing mystery of contemporary cosmology. One wellmotivated particlephysics solution is provided by the hypothesis of axions, very weakly interacting and very lowmass particles, that would simultaneously explain why quantumchromodynamics perfectly respects the symmetry between matter and antimatter ("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 1214 (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 manybody 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 manybody statistical physics has provided us with quasiexact 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 
