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Calendar of Physics Talks Vienna
| Speaker: | Vishnu Jejjala (University of the Witwatersrand, Johannesburg, South Africa) |
| Abstract: | Non-extremal black holes, which emit thermal Hawking radiation, have two horizons: the event horizon or outer horizon and the Cauchy horizon or inner horizon. Surprisingly, for a broad class of solutions to the Einstein equations, the product of the areas of the inner and outer horizons is the square of the area of the horizon of the zero temperature black hole obtained from taking the smooth extremal limit. We use the attractor mechanism in supergravity to motivate this result. Non-extremal geometries at the Reissner-Nordström point, where the scalar moduli are held fixed, can be lifted to solutions in supergravity with a near-horizon AdS3×S2. These solutions have the same entropy and temperature as the original black hole and therefore allow an interpretation of the underlying gravitational degrees of freedom in terms of CFT2. |
| Date: | Mon, 21.11.2016 |
| Time: | 14:30 |
| Duration: | 60 min |
| Location: | 10th floor seminar room in yellow tower of TU Wien Freihaus (Wiedner Hauptstrasse 8-10, A-1040 Vienna) |
| Contact: | ayan.mukhopadhyay@tuwien.ac.at |
| Noncommutative spaces and differential geometry |
| Speaker: | Maja Buric (Belgrade Univesity) |
| Abstract: | im Rahmen des Seminars für Mathematische Physik: In the first part of the talk we will discuss the notion of noncommutative spaces from
a physicist's point of view: coherent states, symmetries, differential geometry, gravity
and the classical limit.
In the second part of the talk we will describe some models of noncommutative spaces
which are constructed to be spherically symmetric and curved, in particular, de Sitter space.
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| Date: | Tue, 22.11.2016 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | S. Fredenhagen, H. Steinacker |
| Short-Baseline Neutrino Oscillation Anomalies and Light Sterile Neutrinos |
| Speaker: | Carlo Giunti (INFN, Sezione di Torino) |
| Date: | Tue, 22.11.2016 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, W. Grimus |
| Nuclear Physics of Neutrinos: About double-beta decay and solar neutrinos |
| Speaker: | Prof. Dr. Dieter Frekers (Universität Münster) |
| Abstract: | Double-beta decay is a process, which occurs inside a nucleus, and one of the great challenges is to understand the response of the nuclear many-body system when two neutrons suddenly convert to two protons. This transition is generally described through what is called the “nuclear matrix element (NME)” of double-beta decay, and this quantity directly enters into the decay rates equation. The two-neutrino double-beta decay is a low-momentum transfer phenomenon and the NMEs can be easily measured through charge-exchange reactions. The much more important zero-neutrino double-beta decay is a high-momentum transfer phenomenon and experimentally little is known about the nuclear response. In fact, the present situation of the NMEs for the neutrinoless double-beta decay is profoundly disconcerting.
In this talk...
[ for full abstract please visit: https://indico.smi.oeaw.ac.at/event/210/ ] |
| Date: | Wed, 23.11.2016 |
| Time: | 17:00 |
| Duration: | 60 min |
| Location: | Stefan-Meyer-Institut, Boltzmanngasse 3, 1090 Wien, Seminarraum 3-2-08 (2. Stock) |
| Contact: | Prof. Dr. Eberhard Widmann, Dr. Martin Simon |
| Speaker: | Daniel Grumiller (TU Vienna) |
| Abstract: | im Rahmen des Literaturseminars der Gravitationsphysik: The notion of "soft hair" refers to zero energy excitations in the near horizon region of black holes or cosmologies, advocated by Hawking, Perry and Strominger. I review recent results on soft hair in three spacetime dimensions. In particular, I focus on the near horizon symmetry algebra, which turns out to be surprisingly simple, namely infinite copies
of the Heisenberg algebra. The results are universal (in a sense that I shall make precise)
and could generalize to higher dimensions. Talk based on arXiv papers 1603.04824, 1607.00009, 1607.05360.
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| Date: | Thu, 24.11.2016 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
| Fusion of Interfaces in Landau-Ginzburg models |
| Speaker: | Stefan Fredenhagen (Univ. Wien) |
| Abstract: | Interfaces provide interesting structures in two-dimensional field theories. A particular operation is the fusion of two interfaces. In the example of N=2 Landau-Ginzburg models we can describe (B-type)-interfaces by matrix factorisations, and the fusion of such factorisations amounts to taking their tensor product. In the talk I will review these concepts and introduce an alternative functorial formulation of some interfaces which is tailored to give a simplified description of fusion. |
| Date: | Thu, 24.11.2016 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | Institute for Theoretical Physics, TU Wien, Seminar room, 10th floor, Wiedner Hauptstr. 8-10, 1040 Wien |
| Contact: | Johanna Knapp |
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