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Calendar of Physics Talks Vienna
| The anti-Unruh effect in black hole spacetimes |
| Speaker: | Aindriu Conroy (Charles University, Prague) |
| Abstract: | There is no well-defined notion of a particle in quantum field theory in curved spacetime due to the lack of global symmetries.The standard procedure in quantum field theory is to treat fields rather than particles as the fundamental object of interest.Nevertheless in a seminal 1976 paper by W.G. Unruh,an operational meaning was given to the particle concept by examining the absorption and emission of field quanta by a two-level atom.This is the so-called Unruh-DeWitt detector and, in this operational sense,we say a particle is what a particle detector detects!Computing the response of an Unruh-DeWitt detector in black hole spacetimes is technically challenging â a fact which has largely limited the literature to stationary detectors.In this talk we consider the response of an Unruh-DeWitt detector near an extremal charged black hole,modelling the near-horizon region of this extremal ... |
| Date: | Tue, 10.01.2023 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock |
| Contact: | S. Fredenhagen, D. Grumiller, E. Battista, R. Ruzziconi |
| The cosmological constant, anomalies and an emergent Standard Model |
| Speaker: | Steven Bass (Jagiellonian University, Krakow) |
| Abstract: | We discuss the Higgs mass and cosmological constant hierarchy puzzles with emphasis on the
interplay of Poincare invariance, mass generation and renormalization group invariance.
A plausible explanation involves an emergent Standard Model with the cosmological constant scale
suppressed by power of the large scale of emergence. In this scenario the cosmological constant scale
0.002 eV and (Majorana) neutrino masses should be of similar size. |
| Date: | Tue, 10.01.2023 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, M. Procura |
| Obstruction-free gluing for the Einstein equations |
| Speaker: | Stefan Czimek, Leipzig |
| Abstract: | We present a new approach to the gluing problem in General Relativity, that is, the problem of matching two solutions of the Einstein equations along a spacelike or characteristic (null) hypersurface.
In contrast to previous constructions, the new perspective actively utilizes the nonlinearity of the constraint equations. As a result, we are able to remove the 10-dimensional spaces of obstructions to
gluing present in the literature. As application, we show that any asymptotically flat spacelike initial data set can be glued to Schwarzschild initial data of sufficiently large mass. This is joint work with I. Rodnianski. |
| Date: | Thu, 12.01.2023 |
| Time: | 15:15 |
| Duration: | 60 min |
| Location: | Seminarraum A, Währinger Strasse 17, 2. Stock |
| Contact: | P. Chrusciel, D. Fajman |
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