CPT

Calendar of Physics Talks Vienna

Do classical de Sitter string backgrounds exist?
Speaker:David Andriot (TU Wien)
Abstract:A classical solution of string theory with a 4d de Sitter space-time could provide a simple and well-controlled setting to establish a connection to cosmological models. So far however, it has proven very difficult to find any example of such a solution. As will be recalled, attempts in this direction are plagued by many no-go theorems, or by the difficulty for concrete 10d supergravity solutions to fit in the classical stringy regime. This situation agrees with the recent claims of de Sitter swampland conjectures. These conjectures can actually be verified quantitatively, with a surprisingly good agreement, as will be shown. This may hint at a deep reason against classical de Sitter background, possibly to be found within the web of swampland conjectures, and the relation to the distance conjecture will be commented on.
Date: Tue, 17.11.2020
Time: 14:00
Location:https://moodle.univie.ac.at/mod/bigbluebuttonbn/guestlink.php?gid=x8o6ILSKJuC9
Contact:Thorsten Schimannek

Particle Physics: a panorama circa 2020
Speaker:Prof. Paris Sphicas (CERN, National and Kapodistrian University of Athens)
Abstract:I will review the current state of the field of High Energy Physics, as it was presented at the recent ICHEP 2020 conference (August 2020). The talk will present highlights from the energy and intensity frontiers, as well as bit from the cosmic frontier. I will aspire to provide a broad-brush picture of the current HEP landscape, with reference to recent noteworthy results and expectations for the coming decade. The talk is based on the conference summary talk given at ICHEP2020. [additional details here: https://indico.smi.oeaw.ac.at/event/381/]
Date: Wed, 18.11.2020
Time: 16:30
Duration: 60 min
Location:Joint HEPHY/SMI Webinar: request zoom link by 17Nov2020 via email martin.simon at oeaw.ac.at
Contact:Prof. Dr. Eberhard Widmann, Dr. Martin Simon, Prof. Dr. Jochen Schieck, Dr. Florian Pitters

The Effective Field Theory for Hydrodynamics and its Analytic Properties
Speaker:Ashish Shukla (Perimeter)
Abstract:Hydrodynamics provides an effective description for many-body systems near thermal equilibrium. The success of the paradigm rests on the idea that the dynamics of such near-equilibrium systems can be captured by a very small number of parameters, such as the temperature and fluid velocity, and their derivatives. For instance, relativistic hydrodynamics, which is applicable to systems which respect the Lorentz symmetry, has been immensely successful in understanding the properties of the Quark-Gluon plasma that is produced in heavy-ion collisions at RHIC and CERN. In this talk, I will start by reviewing the construction of hydrodynamics in terms of a derivative expansion, followed by a discussion of the equilibrium generating functional and its properties. [...]
Date: Thu, 19.11.2020
Time: 16:00
Duration: 60 min
Location:https://tuwien.zoom.us/j/95482849369?pwd=SkU2WU5hMVJBQWsyVlFXRlRvQlIvdz09
Contact:Laura Donnay, Anton Rebhan

The gravitating kinetic gas - Lifting the Einstein Vlasov system to the tangent bundle
Speaker:Christian Preifer (Univ. Tartu, Estland)
Abstract:In this talk I will present a new model for the description of a gravitating kinetic gas,by coupling the 1-particle distribution function (1PDF)of the gas directly to the gravitational field,lifted to the tangent bundle of spacetime.This procedure takes the influence of the velocity distribution of the kinetic gas particles on their gravitational field fully into account,instead of only on average,as it is the case for the Einstein-Vlasov system.By using Finsler spacetime geometry I construct an action for the kinetic gas on the tangent bundle,which is added as matter action to a canonical Finslerian generalisation of the Einstein-Hilbert action.The invariance of the kinetic gas action under coordinate changes gives rise to a new notion of energy-momentum conservation of a kinetic gas in terms of an energy-momentum distribution tensor. The variation of the total action with ...
Date: Thu, 19.11.2020
Time: 16:00
Duration: 60 min
Location:ZOOM https://zoom.us/j/4200372900?pwd=c01vb0FNRU94V0JVdWlnaDE0eUwwQT09
Contact:Piotr Chrusciel, David Fajman