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Calendar of Physics Talks Vienna
| Conformal Renormalization of anti-de Sitter gravity |
| Speaker: | Rodrigo Olea (Universidad Andrés Bello, Chile) |
| Abstract: | Boundary counterterms are required to cancel the divergences in the bulk action of asymptotically AdS gravity. These boundary terms are prescribed by a systematic procedure known as Holographic Renormalization, developed in the context of AdS/CFT correspondence. In this seminar, we show that, in four and six bulk dimensions, these counterterms can also be obtained from a proper embedding of Einstein in Conformal gravity (Conformal Renormalization). |
| Date: | Tue, 15.10.2024 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Sem.R. DC rot 07 (7th floor, red sector) |
| Contact: | Daniel Grumiller, Ankit Aggarwal |
| Non-regular spacetime geometry via metric geometry and optimal transport |
| Speaker: | Clemens Sämann (University of Vienna) |
| Abstract: | I present an approach to Lorentzian geometry and General Relativity that does neither rely on smoothness nor on manifolds, thereby leaving the framework of classical differential geometry. This opens up the possibility to study curvature (bounds) for spacetimes of low regularity or even more general spaces.
An analogous shift in perspective proved extremely fruitful in the Riemannian case (Alexandrov-, CAT(k)- and CD-spaces). Using strategies from metric geometry and tools from optimal transport this approach to non-regular spacetime geometry has given rise to a fresh and very active line of research. I will report on its progress and, if time permits, give an outlook on future directions.
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| Date: | Tue, 15.10.2024 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | S. Fredenhagen, M. Sperling |
| Turbulent Cascades and condensation in Hamiltonian systems |
| Speaker: | Anxo Biasi (Ecole Normale Superieure-PSL) |
| Abstract: | This talk concerns the problems of energy concentration and structure formation in Hamiltonian systems. I will present a novel mechanism for the dynamical formation of condensates, which markedly differs from that predicted by the wave turbulence theory. I will also show that the process is accompanied by a deterministic turbulent cascade that concentrates energy at arbitrarily small scales in finite time. The result is fully analytic, based on explicit solutions representing all the aforementioned phenomena. This talk is based on my recent work: Phys. Rev. E 110, 034107 (2024). |
| Date: | Wed, 16.10.2024 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Seminarraum A, Waehringer Strasse 17, 2nd Floor |
| Contact: | Piotr T. Chrusciel, David Fajman |
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