|
Calendar of Physics Talks Vienna
| New symmetries for general relativity |
| Speaker: | Simone Speziale (Marseille, CPT) |
| Abstract: | In the last few years there has been a lot of interest in asymptotic
symmetries in gauge theories and general relativity, in relation with
deep infrared physics and memory effects. I will first give a brief
pedagogical introduction showing how the surface charges associated
with asymptotic symmetries follow from a standard application of
Noether's theorem, and then discuss three extensions of the BMS
symmetries that have been proposed in the context of general
relativity, with their motivations. Among the new results, an
algebraic perspective on
the flux-balance laws of gravitational waves,
a proposed modification of the Barnich-Troessaert bracket for the charges,
and the possibility of discriminating bulk-equivalent descriptions of
gravity such as
metric and tetrad formulations, with some speculative implications for
quantum gravity. |
| Date: | Tue, 15.03.2022 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Sem.R. DA, gruen 05 (TU Wien, Freihaus) |
| Contact: | D. Grumiller, S. Fredenhagen, E. Battista, R. Ruzziconi |
| Integrating out heavy fields in the path integral using the background-field method |
| Speaker: | Maximilian Stahlhofen (Freiburg University) |
| Abstract: | I will describe a state-of-the-art functional integration approach to integrate out heavy fields of beyond Standard Model (BSM) theories at one-loop level.
The operators of the resulting effective field theory (EFT) encode the effects of the heavy loops in their Wilson coefficients.
The method is based on the background-field formalism and the expansion by regions.
As an illustrative example I will discuss the matching of a singlet extension of the Standard Model onto the Standard Model EFT (SMEFT).
I will particularly focus on issues related to the mixing of Higgs fields in the BSM model.
In this context a proper scheme choice for the renormalization of tad poles and mixing angles turns out to be crucial.
|
| Date: | Tue, 15.03.2022 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | Erwin-Schrödinger-HS, Fakultät für Physik, Boltzmanngasse 5, 5. Stock sowie ZOOM https://univienna.zoom.us/j/93427906843?pwd=YjhSejdUVW16QjVQYUh5TVNSNFNhQT09 |
| Contact: | A. Hoang, M. Procura |
| Gravitational instantons and special geometry |
| Speaker: | Lars Andersson (Albert Einstein Institut, Golm) |
| Abstract: | Gravitational instantons are Ricci flat complete Riemannian 4-manifolds with at least quadratic curvature decay.
In this talk I will introduce some notions of special geometry, discuss known examples, and mention some open questions.
The Chen-Teo gravitational instanton is an asymptotically flat, toric, Ricci flat family of metrics on $\mathrm{CP}^2 \setminus \mathrm{S}^1$,
that provides a counterexample to the classical Euclidean Black Hole Uniqueness conjecture. I will sketch a proof that the Chen-Teo Instanton is Hermitian and non-Kähler.
Thus, all known examples of gravitational instantons are Hermitian. This talks is based on joint work with Steffen Aksteiner, cf. https://arxiv.org/abs/2112.11863. |
| Date: | Thu, 17.03.2022 |
| Time: | 15:00 |
| Duration: | 60 min |
| Location: | ZOOM https://univienna.zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09 Meeting ID: 654 003 6841 Passcode: Gs4brS |
| Contact: | P. Chrusciel, D. Fajman |
| Stringtheorie und die Geometrisierung der Quantenphysik |
|