|
Calendar of Physics Talks Vienna
| Covariant Quantum Spaces, Matrix Models and Gravity |
| Speaker: | Harold Steinacker (Univ. Wien) |
| Abstract: | I will discuss geometrical properties and physical perspectives of 4-dimensional covariant quantum spaces, focusing on the fuzzy 4-sphere. These spaces realize quantum geometries with local and global symmetries. The fluctuations on such
a background within the IKKT matrix model lead to a higher spin theory, due to
the underlying twisted bundle structure. Some aspects of the gravitational sector
are elaborated, and the linearized Einstein equations modified by an IR cutoff are extracted under some assumptions.
|
| Date: | Tue, 04.04.2017 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | S. Fredenhagen, H. Steinacker |
| The MSR Mass and the ℴ(ΛQCD) Renormalon Sum Rule |
| Speaker: | Christopher Lepenik (Univ. Wien) |
| Abstract: | im Rahmen des Teilchenphysik-Seminars |
| Date: | Tue, 04.04.2017 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, H. Neufeld |
| Speaker: | Juan Valiente-Kroon (Queen Mary) |
| Abstract: | In this talk I will give an overview of Friedrich’s construction of a regular asymptotic initial value problem at spatial infinity and the open questions related to it. In particular, I will show how this framework can be used to identify initial data sets for the vacuum Einstein field equations which should lead to spacetimes not satisfying the peeling behaviour. This is research in collaboration with Edgar Gasperin. |
| Date: | Thu, 06.04.2017 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
| Universal corrections to entanglement entropy of local quantum quenches and scrambling time |
| Speaker: | Surbhi Khetrapal (Centre for High Energy Physics, Indian Institute of Science) |
| Abstract: | We study the time evolution of single interval Renyi and entanglement entropies following local quantum quenches in 2d CFTs at finite temperature for which the locally excited states have a finite temporal width, epsilon. We show that, for local quenches produced by the action of a conformal primary field, the time dependence of Renyi and entanglement entropies at order epsilon^2 is universal. It is determined by the expectation value of the stress tensor in the replica geometry and proportional to the conformal dimension of the primary field generating the local excitation. We also show that in CFTs with a gravity dual, the epsilon^2 correction to the holographic entanglement entropy following a local quench precisely agrees with the CFT prediction. We compute another correction when the CFT has higher spin chemical potential, and find that its time dependence is universal.
...
|
| Date: | Thu, 06.04.2017 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | SEM 136, TU Wien, Freihaus, 10th floor (Wiedner Hauptstr. 8-10, A-1040 Vienna) |
| Contact: | Daniel Grumiller and Johanna Knapp |
|