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Calendar of Physics Talks Vienna
| Quantum gravity at the corner |
| Speaker: | Laurent Freidel (Perimeter Institute for Theoretical Physics) |
| Abstract: | In this talk, I will present a new perspective on the non-perturbative
quantization of gravity based on the concept of corner symmetries associated with local subregions.
After introducing the corner algebra for various formulations of general relativity, I will illustrate its physical content in 4d metric and tetrad gravity. I will also present the formalism of edge modes, whose role is to restore gauge-invariance at boundaries while preserving non-trivial charges. If time permits, I'll show our recent progress on the representation theory of these algebras. I will also describe the relationship that these results entertain with standard loop gravity, asymptotic quantization, and the concept of holography. |
| Date: | Tue, 08.12.2020 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Online https://moodle.univie.ac.at/mod/bigbluebuttonbn/guestlink.php?gid=x8o6ILSKJuC9 |
| Contact: | Céline Zwikel |
| Investigation of stationary n-black-hole configurations with soliton methods |
| Speaker: | Joerg Hennig (Otago) |
| Abstract: | An intriguing open problem in general relativity is the question as to whether stationary equilibrium configurations with clearly separated bodies can exist.Due to the nonlinear effect of the spin-spin repulsion of rotating objects and perhaps by considering charged objects with an additional electromagnetic repulsion,it remains a possibility that such unusual configurations do exist.An important example of an n-body system is a(hypothetical)equilibrium configuration with n aligned rotating and possibly charged black holes. By studying the linear matrix problem that is equivalent to the Einstein(-Maxwell)equations for axixymmetric and stationary(electro)vacuum spacetimes we obtain the most general form of the boundary data on the symmetry axis in terms of a finite number of parameters.This will be illustrated with the simplest case of one black hole in vacuum and we briefly discuss how.. |
| Date: | Thu, 10.12.2020 |
| Time: | 10:00 |
| Duration: | 60 min |
| Location: | ZOOM https://zoom.us/j/92376135485?pwd=LzlUemhvcU5rL0hhZGxPOUVieDgxZz09 |
| Contact: | Piotr Chrusciel, David Fajman |
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