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Calendar of Physics Talks Vienna
| The Role of Sources in Flat Space Holography (Vienna Theory Lunch Seminar) |
| Speaker: | Adrien Fiorucci (TU Wien) |
| Abstract: | The aim of this talk is to review the main obstacles to the construction of flat space holography on the basis of the celebrated AdS/CFT correspondence â namely the null nature of the conformal boundary and the non-conservation of gravitational charges in the presence of radiation â and to discuss how to deal with them. It will be argued that the putative holographic dual theory is a Carrollian conformal field theory, coupled to external sources that account for the radiation reaching the boundary. To formalise this coupling, a generalised concept of variational symmetries must be introduced, for which Noetherâs first theorem yields flux-balance laws instead of conservation laws. Some implications of this new formalism will be discussed, both in classical mechanics and in quantum field theory. [[part of the "Vienna Theory Lunch Seminar, see https://lunch-seminar.univie.ac.at ]] |
| Date: | Tue, 31.10.2023 |
| Time: | 12:30 |
| Duration: | 75 min |
| Location: | TU Wien: Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room DB10E11 |
| Contact: | Florian Lindenbauer |
| Topology change and heterotic flux vacua |
| Speaker: | Ilarion Melnikov (James Madison Univ. / IPhT Saclay) |
| Abstract: | I will review the status of heterotic flux compactification with 8 and 4 supercharges. The underlying geometry of these compactifications is a principal torus bundle over a K3 surface, and T-duality in the torus fiber leads to equivalences between topologically distinct configurations. In particular, I will argue that all such vacua that preserve 8 supercharges can be related to more conventional (flux free) compactifications. These dualities lead to a rich interconnected web of stringy geometries with a fairly direct worldsheet CFT interpretation.
Orbifolds of such configurations can partially break supersymmetry and reduce the gauge group rank. On the other hand, there are four-dimensional configurations that cannot be T-dualized to configurations without flux; these configurations place strong constraints
on the underlying K3 geometry.
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| Date: | Tue, 31.10.2023 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Sem. R. DB gelb 03 - TU Wien Freihaus, Wiedner Hauptstrasse 8, 3rd floor, yellow tower |
| Contact: | S. Fredenhagen, D. Grumiller, T. Tran, A. Fiorucci |
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