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Calendar of Physics Talks Vienna
| Maximally symmetric spacetimes reconsidered |
| Speaker: | Stefan Prohazka (ULB) |
| Abstract: | Spacetimes, like Minkowski space, are omnipresent in physics. I will introduce a recent classification of spacetimes that generalizes the classification of maximally symmetric lorentzian geometries and includes further physically interesting ones. Among them are galilean, carrollian and aristotelian geometries for which there is renewed interest due to applications in holography. These spacetimes posses infinite dimensional (BMS-like) symmetries which we will also discuss.
Mainly based on: arXiv:1809.01224, arXiv:1903.09165 |
| Date: | Tue, 05.11.2019 |
| Time: | 13:45 |
| Duration: | 60 min |
| Location: | TU Wien - Wiedner Hauptstraße 8 - Red Area, 7th floor, Seminar Room (DC 07 A15) |
| Contact: | D. Grumiller, S. Fredenhagen |
| Variants and parametrization of self-interacting dark matter |
| Speaker: | Xiaoyong Chu (HEPHY, Wien) |
| Abstract: | Im Rahmen des Teilchenphysikseminars: Cosmological simulations suggest that there exists an unexpected mass deficit in dark matter inner halos. This has inspired the study of self-scattering dark matter. In this talk, I will first discuss various dark matter models that can address such mass deficit while satisfying other observational bounds, such as self-interactions enhanced by light mediators, or by a s-wave resonance, at low velocities. The second half of my talk will introduce the so-called effective-range approach, which describes the velocity dependence of the self-interaction cross section in a model-independent way, with only two parameters. |
| Date: | Tue, 05.11.2019 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, S. Plätzer |
| CLIC - From the machine to the science |
| Speaker: | Erica Brondolin (CERN) |
| Abstract: | The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear electron- positron collider under study at CERN. For an optimal exploitation of its physics potential, CLIC is foreseen to be built and operated in three stages, at centre-of- mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. Each of the three energy stages adds cornerstones of the full CLIC physics programme, such as Higgs width and couplings, top-quark properties, Higgs self-coupling, and searches for new phenomena through direct and indirect measurements. The construction of the first CLIC energy stage could start by 2026 and first beams would be available by 2035. An overview of the CLIC project, its physics potential and the design, technology, and implementation aspects of the accelerator and the detector will be presented. |
| Date: | Thu, 07.11.2019 |
| Time: | 09:30 |
| Duration: | 60 min |
| Location: | HEPHY Library |
| Contact: | Josef Pradler |
| Linear stability of slowly rotating Kerr spacetimes |
| Speaker: | Dietrich Haefner (Grenoble, Frankreich) |
| Abstract: | In joint work with Peter Hintz and András Vasy, we study the asymptotic behavior of linearized gravitational perturbations of Schwarzschild and slowly rotating Kerr black hole spacetimes. We show that solutions of the linearized Einstein equation decay at an inverse polynomial rate to a stationary solution (given by an infinitesimal variation of the mass and angular momentum of the black hole), plus a pure gauge term. In this talk,
I will describe the geometric background and the analytic setup of our result, including
a discussion of gauge fixing. Our proof is based on a precise description of the resolvent of an associated wave equation on symmetric 2-tensors near zero energy.
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| Date: | Thu, 07.11.2019 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel, D. Fajman |
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