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Calendar of Physics Talks Vienna
| Space-time curvature-induced corrections to Rytov's law in optical fibers (Vienna Theory Lunch Seminar) |
| Speaker: | Mario Hudelist (Universität Wien) |
| Abstract: | According to Rytov's law, the polarization vector of light follows a Fermi-Walker transport equation in optical fibers. Recent advancements in theory propose a modification to Rytov's law due to fiber bending. The aim of this talk is to further extend these predictions from flat to curved space-time. This involves perturbatively solving Maxwell's equations under the assumption that the wavelength is significantly shorter than the fiber radius, as well as the characteristic length-scales of the ambient space-time. This results in a coupling of the polarization vector to the Riemann curvature tensor.
[[part of the "Vienna Theory Lunch Seminar, see https://lunch-seminar.univie.ac.at ]] |
| Date: | Tue, 19.03.2024 |
| Time: | 12:30 |
| Duration: | 75 min |
| Location: | University of Vienna, Boltzmanngasse 5, 5th floor, Schrödinger Lecture Hall |
| Contact: | Florian Lindenbauer |
| Covariant charges and fluxes at null infinity. |
| Speaker: | Antoine Rignon-Bret (Universite d'Aix-Marseille) |
| Abstract: | In this talk, I will review the application of Noether theorem to general relativity and the covariant phase space techniques to construct Noether charges and fluxes on spacetime boundaries. In particular, I will detail the Wald-Zoupas procedure and focus on the physical interpretation. I will show that the implementation of the procedure implies that the algebra of local Noether currents is free of cocycle. Then, I will focus on non-trivial examples at null infinity. I will implement the Wald-Zoupas procedure for BMS and eBMS boundary conditions, and argue that it cannot be implemented successfully for generalized BMS fall-off conditions but for a symmetry group preserving different fall off conditions isomorphic to gBMS with a different algebra.
[[NB. The seminar will also be streamed in the Schroedinger-Hoersaal. For ZOOM attendees: Meeting ID: 420 707 3557, Password: Q4Tfue5N]] |
| Date: | Tue, 19.03.2024 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Online (ZOOM). Link : https://tuwien.zoom.us/j/4207073557?pwd=YVhUSVpZRnRMR3p0aXdsb1BmaXFwUT09&omn=64465475582 |
| Contact: | Adrien Fiorucci, Daniel Grumiller |
| "EW corrections in SMEFT" |
| Speaker: | Benjamin Pecjak (University of Durham) |
| Abstract: | Standard Model Effective Field Theory (SMEFT) is not only a practical tool for searching for small deviations from SM expectations in data, but is also a well-defined quantum field theory.
In this talk I focus on interesting field-theoretical features involved in calculations of EW corrections in SMEFT. Compared to the SM, these include subtleties in Higgs-Z mixing, electric charge renormalisation,gauge fixing, and the treatment of tadpoles when using hybrid renormalisation schemes where some parameters are renormalised in the MS-bar scheme and some in the on-shell scheme.
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| Date: | Tue, 19.03.2024 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Broggio |
| Gravitational memory effects for particles and wave packets |
| Speaker: | Marius Oancea ((U of Vienna)) |
| Abstract: |
Gravitational waves can generally influence the dynamics of test objects with which they interact. Changes in the relative dynamics of test objects can persist even after the gravitational wave has passed and spacetime is again flat. These are generally referred to as gravitational memory effects, since the properties of the passing gravitational wave remain encoded in the relative dynamics of test objects. In this talk, I will discuss gravitational memory effects in plane wave spacetimes for different classes of test objects: particles following geodesics, spinning particles with non-geodesic motion, and test scalar fields. For all these objects, memory effects are encoded into a set of four memory tensors that depend on the gravitational wave profile.
Joint work with Abraham Harte, Thomas Mieling, and Florian Steininger. |
| Date: | Wed, 20.03.2024 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Seminarraum A, Waehringer Strasse 17, 2nd Floor |
| Contact: | Piotr T. Chrusciel |
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