CPT

Calendar of Physics Talks Vienna

M-brane Realisation in Matrix Model
Speaker:Yuhma Asano (Universität Wien)
Abstract:In this talk, we consider a one-dimensional matrix model, called the BMN matrix model, which is considered as a non-perturbative formulation of M-theory. In the BMN matrix model, there are some evidences that spherical M2- and M5-branes correspond to vacua of the matrix model. While it is easy to understand realisation of M2-brane geometries because the vacua form fuzzy 2-spheres, it requires non-perturbative computation in a strongly coupled regime to obtain realisation of M5-brane geometries. We solve this notorious problem by using the supersymmetric localisation method and see how the M-brane geometries are successfully obtained. Intriguingly, this result gives us a consistent picture of how the gravity-side spacetime in the gauge/gravity correspondence emerges from the matrix model.
Date: Tue, 03.11.2020
Time: 14:00
Duration: 60 min
Location:https://moodle.univie.ac.at/mod/bigbluebuttonbn/guestlink.php?gid=x8o6ILSKJuC9
Contact:Thorsten Schimannek

Smoothing and Flattening the Universe
Speaker:Paul Steinhardt (Princeton U.)
Abstract:The most salient feature of the observable universe is that it is homogeneous and spatially flat on large scales. This talk will argue why this may only be explained by replacing the big bang with a big bounce preceded by a period of slow contraction, a conclusion which has profound implications for cosmology and fundamental physics.
Date: Thu, 05.11.2020
Time: 16:00
Duration: 60 min
Location:https://tuwien.zoom.us/j/95482849369?pwd=SkU2WU5hMVJBQWsyVlFXRlRvQlIvdz09
Contact:Laura Donnay, Niccolo Cribiori, David Andriot

On the structure and strength of singularities: Inextendibility results for Lorentzian manifolds
Speaker:Jan Sbierski (Oxford)
Abstract:Given a solution of the Einstein equations a fundamental question is whether one can extend the solution or whether the solution is maximal. If the solution is inextendible in a certain regularity class due to the geometry becoming singular, a further question is whether the strength of the singularity is such that it terminates classical time-evolution.
Date: Thu, 05.11.2020
Time: 17:00
Duration: 60 min
Location:ZOOM https://zoom.us/j/4200372900?pwd=c01vb0FNRU94V0JVdWlnaDE0eUwwQT09
Contact:Piotr Chrusciel, David Fajman