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Calendar of Physics Talks Vienna
| Double Field Theory and Membrane Sigma Models |
| Speaker: | Athanasios Chatzistavrakidis (Rudjer-Boskovic-Institute Zagreb) |
| Abstract: | Double Field Theory (DFT) promotes the T-duality for closed strings to a manifest
symmetry and it can describe the generalised geometries that a closed string may
experience. In this talk, we discuss the world volume theory and the geometry that
corresponds to the DFT structure. Utilizing the one-to-one correspondence between
Courant algebroids and a class of Membrane Sigma Models (MSMs), we construct
the MSM for DFT as a projection of a Courant sigma model over a doubled space.
This model contains all types of geometric and non-geometric fluxes as generalised
Wess-Zumino terms and its gauge structure gives rise to the DFT Bianchi identities
and the DFT strong constraint. Moreover, this offers a geometric description of DFT
as a structure that lies in between two Courant algebroids over different bases.
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| Date: | Tue, 21.11.2017 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | TU Wien, Freihaus, SEM 136, 10. Stock, Wiedner Hauptstr. 8-10, 1040 Wien |
| Contact: | S. Fredenhagen, D. Grumiller |
| Soft and hard multiple interactions in hadronic collisions |
| Speaker: | Stefan Gieseke (KIT) |
| Abstract: | im Rahmen des Teilchenphysikseminars |
| Date: | Tue, 21.11.2017 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | H. Neufeld, S. Plätzer |
| General Sobolev metrics the on manifold of all Riemannian metrics |
| Speaker: | Peter Michor (Vienna) |
| Abstract: | For a compact manifold Mm equipped with a smooth fixed background
Riemannian metric bg we consider the space MetHs(bg)(M) of all Riemannian metrics of Sobolev class Hs for real s > m 2 with respect to bg. The L2-metric on MetC1(M) was considered by DeWitt, Ebin, Freed and Groisser, Gil-Medrano and Michor, Clarke. Sobolev metrics of integer order on MetC1(M) were considered in [M.Bauer, P.Harms, and P.W. Michor: Sobolev metrics on the manifold of all Riemannian metrics. J. Differential Geom., 94(2):187-208, 2013.] In this talk we consider variants of these Sobolev metrics which include Sobolev metrics of any positive real (not integer) order s > m 2 . We derive the geodesic equations and show that they are well-posed under some conditions and induce a locally diffeomorphic geodesic exponential mapping.
Based on collaborations with M.Bauer, M.Bruveris, P.Harms. |
| Date: | Thu, 23.11.2017 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
| Non-linear supersymmetry and D-term breaking |
| Speaker: | Niccolo Cribiori (Padova University) |
| Abstract: | Non-linear realizations revealed to be a convenient tool for the analysis of models with broken supersymmetry, both in the global and in the local case. Particular attention has been devoted to the studying of inflation and to the description of de Sitter phases in supergravity and string theory.
One possible way to implement non-linear realizations of supersymmetry consists in imposing constraints on multiplets.
In this talk I am concentrating on N=1 supergravity in four dimensions and, after reviewing the main ingredients of the constrained multiplets formalism, I am going to to show how models with D-term breaking can be recast into equivalent ones with F-term breaking. |
| Date: | Thu, 23.11.2017 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | 10th floor seminar room in yellow tower of TU Wien Freihaus (Wiedner Hauptstrasse 8-10, A-1040 Vienna) |
| Contact: | Timm Wrase |
| Quantum Geometrodynamics of Einstein and Conformal Gravity |
| Speaker: | Claus Kiefer (University of Cologne) |
| Abstract: | I discuss the canonical quantization of general relativity and Weyl-squared gravity.
I present the classical and quantum constraints and discuss their similarities and differences.
I perform a semiclassical expansion and discuss the emergence of time for the two theories.
While in the first case semiclassical time has a scale and a shape part, in the second case it only has a shape part. I also address the relevance of these results for the general problem
of understanding quantum gravity.
Ref.: C. Kiefer and B. Nikolic, J.Phys.Conf.Ser. 880 (2017) no.1, 012002 (open access)
and references therein
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| Date: | Fri, 24.11.2017 |
| Time: | 11:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
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