CPT

Calendar of Physics Talks Vienna

Glueballs in Holographic QCD
Speaker:Frederic Brünner (Vienna University of Technology)
Abstract:Glueballs, bound states of gluonic degrees of freedom, are a prediction of quantum chromodynamics. Due to lack of theoretical input, they have not yet been established experimentally. We discuss how this problem can be solved within the framework of the AdS/CFT correspondence, a holographic duality between a strongly coupled gauge theory in four dimensions and a string theory in a five-dimensional Anti-de Sitter geometry. We explain how in a particular realization of holographic QCD, the Sakai-Sugimoto model, one can describe glueball interactions and explicitly calculate decay rates relevant for the experimental search.
Date: Tue, 28.01.2014
Time: 12:30
Duration: 60 min
Location:Univ. of Vienna, Faculty of Physics, Boltzmanngasse 5, 5th floor, Erwin Schrödinger Lecture Hall
Contact:Albert Georg Passegger, Peter Poier - www.univie.ac.at/lunch-seminar

Outdoor sound propagation with respect to ground and meteorological effects
Speaker:Dipl.-Ing. Dr. Dieter Hohenwarter (TGM Wien)
Abstract:Outdoor sound propagation influences our life because the noise of cars or railway carriages disturbs a lot of people. Since approximately 30 years, different models have been in use to describe the ground effects in a scientifically correct way. In contrast to this, in Germany and Austria the calculation of noise maps is based on an older sound propagation model (ISO 9613-2). According to other guidelines, sound level should be measured assuming downwind sound propagation, at which the acoustic contribution of the meteorological effects is small. However, in reality the sound from, e.g., a railway spreads in various ways in relation to the wind direction. Sound propagation up to a distance of 200 m south and north of a railway line was measured along with the meteorological situation with a tethered balloon up to a height of 100 m. In the case of upwind sound propagation, differences o
Date: Tue, 28.01.2014
Time: 16:00
Location:Technische Universität Wien, Institut für Angewandte Physik, Seminarraum 134A, Turm B (gelbe Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Ao.Univ.Prof. Dr. Martin Gröschl

Recent advances in applications of gauge/gravity duality
Speaker:Johanna Erdmenger (Max-Planck-Institute for Physics, Munich)
Abstract:Gauge/gravity duality provides a new approach to describing strongly coupled systems. It thus provides new links between string theory and a variety of areas of physics. We give an overview over new developments by considering two examples in particular: First, we consider derivation of a fermionic analogue of the shear viscosity over entropy ratio. We obtain a supercharge diffusion constant related to the hydrodynamic phonino mode associated to spontaneous breaking of supersymmetry by temperature. Second, we present a holographic realisation of the Kondo effect. This may serve as basis for further applications of gauge/gravity duality in condensed matter physics, for instance to time-dependent systems or Kondo lattices.
Date: Tue, 28.01.2014
Time: 16:00
Duration: 60 min
Location:Vienna University of Technology, Wiedner Hauptstr. 8-10, yellow area, 9th floor, seminar room 138C
Contact:Johanna Knapp

On local wellposedness of ideal relativistic and more general fluids
Speaker:Robert Beig (Univ.Wien)
Abstract:im Rahmen des Literaturseminars für Gravitation
Date: Thu, 30.01.2014
Time: 14:15
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock, 1090 Wien
Contact:H. Rumpf

Description of exclusive hadronic tau decays
Speaker:Matthias Jamin (Universitat Autonoma de Barcelona)
Abstract:4. Vortrag im Rahmen der Schrödinger-Gastprofessur 2013
Date: Thu, 30.01.2014
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, H. Neufeld

Mobile impurity in a quantum system
Speaker:Thierry GIAMARCHI (DPMC, University of Geneva)
Abstract:Understanding the physics of a mobile impurity in a quantum system is a long standing problem. Indeed a quantum bath is strongly affecting the properties of the impurity leading at best to renormalized parameters, such as the mass, and potentially to radically new physics. I will discuss this problem for the case of a one dimensional bath for which the Luttinger nature of the bath leads to a novel set of properties, such as sub-diffusion for the impurity. I will also discuss such physics in the light of the experiments on cold atomic gases targeted to probe these issues, and in particular the ones of the Florence and Munich group.
Date: Thu, 30.01.2014
Time: 15:30
Location:TU Wien Atominstitut, Hörsaal, Stadionallee 2, 1020 Wien
Contact:J. Schmiedmayer

Recent Examples of Computational Biophysics and its General Role in the Age of Supercomputers and HPC
Speaker:Siegfried Höfinger (Universität Bologna/Italien)
Abstract:Computer simulations have become a viable tool in contemporary science providing insight into molecular scale detail that otherwise was difficult to gain from purely experimental methods. Particularly interesting are studies of complicated domains, such as for example interfaces, meta-stable condensed phases, crowded environments, steady state compartments, and many more where experimental characterization is hindered by fundamental methodic limitations. In this seminar we want to discuss several recent computational studies that could either help to characterize novel mechanisms or bring into focus atomistic details of processes of general biophysical/biochemical significance. Computational aspects will be highlighted, underlying theoretical concepts outlined, challenging physical questions emphasized and open problems brought up for discussion.
Date: Fri, 31.01.2014
Time: 14:00
Location:Technische Universität Wien, Institut für Angewandte Physik, Seminarraum 134A, Turm B (gelbe Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Ao.Univ.Prof. Dr. Herbert Störi

Uniform Price Strategies to Exploit Positive Network Externalities
Speaker:Wolfgang Dvorak (Univ. Wien)
Abstract:im Rahmen der gemeinsam veranstalteten Seminare "Komplexe Stochastische Systeme" (Univ.Wien) und "Analyse Komplexer Systeme" (Med.Univ.Wien)
Date: Fri, 31.01.2014
Time: 14:15
Duration: 90 min
Location:Medizinische Univ. Wien, Informatikbibliothek, Bauteil 88, E03, Spitalgasse 23, 1090 Wien
Contact:H. Hüffel und Stefan Thurner