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Calendar of Physics Talks Vienna
| Gravitational duality near cosmological space-times |
| Speaker: | Sergio Hörtner (Universidad Autónoma de Madrid) |
| Abstract: | We shall present a SO(2) duality-symmetric form of the linearized ADM action principle on anti de Sitter and Kasner backgrounds. The analysis is based on the two-potential formalism, obtained upon resolution of the Hamiltonian constraints, and generalizes previous works that focused on Minkowski and de Sitter backgrounds. |
| Date: | Tue, 14.05.2019 |
| Time: | 13:45 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | S. Fredenhagen, D. Grumiller |
| Probabilities and Signalling in QFT |
| Speaker: | Jeff Forshaw (Manchester) |
| Abstract: | I will talk about a way to compute transition probabilities that works directly that the level of probabilities and not amplitudes. The formalism guarantees that the initial and final states are always linked by a chain of retarded propagators and it has a nice diagrammatic approach. |
| Date: | Tue, 14.05.2019 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Kleiner Seminarraum, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, S. Plätzer, M. Procura |
| Obstructions to interacting higher-spin gauge theories in three dimensions |
| Speaker: | Stefan Fredenhagen (Univ. Wien) |
| Abstract: | as part of the joint relativity-mathematical physics seminar: Free higher-spin Fronsdal fields generalise Maxwell fields and linearised gravity to higher tensor fields. Whereas for spin-1 and spin-2 there are non-linear completions (e.g. Yang-Mills, gravity), no non-linear, gauge-invariant theory of Fronsdal fields is known. A systematic way to construct them is the Noether procedure in which a gauge invariant action is constructed in a perturbative expansion in powers of the fields.
In three space-time dimensions, there are strong obstructions to construct such an action leading to the conclusion that the interactions of the higher-spin gauge fields are completely fixed by the cubic vertices in the action.
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| Date: | Thu, 16.05.2019 |
| Time: | 13:30 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel, D. Fajman |
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