CPT

Calendar of Physics Talks Vienna

Conformal gravity in four dimensions
Speaker:Iva Lovrekovic (TU Vienna)
Abstract:im Rahmen des Seminars für Mathematische Physik: One of the very interesting theories of gravity today is conformal gravity. It introduces an issue which is existence of ghosts, however, as higher derivative gravity, it resolves the issue of two loop non-renormalizability in Einstein gravity. It has encouraged scientists as Nobel prize winner t’Hooft or notable physicist Maldacena to research it. We introduce conformal gravity and AdS/CFT correspondence in which it is considered, show that conformal gravity is well defined theory and compute its charges, outline how they define the algebra of the field theory at the boundary, and compute the correction to the key quantity in “AdS/CFT”, partition function.
Date: Tue, 11.10.2016
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:S. Fredenhagen, H. Steinacker

Top Quark Mass Calibration for Monte-Carlo Event Generators
Speaker:Moritz Preißer (Univ. Wien)
Abstract:im Rahmen des Teilchenphysikseminars: The lack of knowledge how the top quark mass parameter in Monte-Carlo event generators (MCs) is related to field theoretically defined mass schemes limits the theoretical interpretation of very precise top quark mass determinations at hadron colliders which are based on direct reconstruction. After reviewing the conceptual problems I will describe a method to calibrate the measured top quark MC mass parameter by fits of MC hadron level predictions for observables with very strong mass sensitivity to corresponding hadron level QCD predictions. Subsequently I will demonstrate the approach for 2-jettiness in e+e- annihilation and show the calibration results for m_t^MC in Pythia 8.205 for the MSR mass at the scale 1 GeV and the pole mass at NNLL+NLO accuracy.
Date: Tue, 11.10.2016
Time: 16:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, H. Neufeld

Quantum Optics with Molecules and Nanoparticles: Opportunities and open debates around gravity physics and cosmology
Speaker:Markus Arndt (Univ. Wien)
Abstract:I will review the state of the art in atom and macromolecule interferometry to stimulate discussions on quantum physics, gravity and cosmology. A large part of the talk will be dedicated to open questions the correct answers to which I do not know at all: Do wave functions collapse ‘objectively’ when objects become massive and delocalized over large periods of time? How would this influence the temperature of the universe? Why does mass do if nobody watches? How could the universe not watch at all? How will the gravitational warp of space-time modify the linearity of Schrödinger’s wave mechanics for very massive and highly delocalized clusters? Is there any chance of observing fluctuations of space time in matter-wave interferometry? Can we use nanoparticle matter-waves for gravitational wave detection? What do we learn about the weak equivalence principle and possible modifications ....
Date: Thu, 13.10.2016
Time: 14:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Victor-Franz-Hess-Hörsaal, VERA 1. Stock
Contact:P.T. Chrusciel, A. Hoang, S. Fredenhagen

Next Steps in Cosmology with the CMB
Speaker:Jens Chluba (University of Manchester)
Abstract:The cosmic microwave background (CMB) has proven to be an amazing source or information about the Universe we live in. Beyond any doubt, in the next decades studies of the CMB polarization anisotropies and the CMB energy spectrum will reveal many exciting new pieces to the puzzle. I will give a broad-brush overview of the next steps in cosmology with the CMB, in particular highlighting the immense potential of studies of the CMB spectrum and its complementarity with CMB anisotropies.
Date: Fri, 14.10.2016
Time: 10:30
Duration: 60 min
Location:HEPHY, Wohllebengasse 12-14 ( Seminar Room )
Contact:Josef Pradler