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Calendar of Physics Talks Vienna
| Should photon mass be zero |
| Speaker: | Prof. T.R. Govindarajan (Chennai, Indien) |
| Abstract: | We revisit the question of gauge invariance, infrared divergence and asymptotic
symmetries in QED. By introducing a mass for the photon we can avoid the problems
of divergence. This can be done in a gauge invariant way using Stückelberg field.
This is done in 2+1 and 3+1 dimensions as models. We explore the role of this field
in new symmetries and possible role in cosmology. We extend similar questions to
gravity also.
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| Date: | Tue, 12.06.2018 |
| Time: | 13:45 |
| Duration: | 60 min |
| Location: | TU Wien, Freihaus, SEM 136, 10. Stock, Wiedner Hauptstr. 8-10, 1040 Wien |
| Contact: | S. Fredenhagen, D. Grumiller |
| Hot-electron interactions with non-collinear surface spins revealed via image-potential states |
| Speaker: | Anika Schlenhoff (Department of Physics, University of Hamburg/Germany) |
| Abstract: | Understanding the interactions of hot electrons with localized spins is an important prerequisite for the development of spintronic applications. A model system to investigate these interactions are image-potential states (IPS) forming a Rydberg-like series of unoccupied states in front of surfaces [1]. Using a spin-polarized scanning tunneling microscope (SP-STM) in the field emission mode, we locally investigate IPS above magnets with non-collinear spin textures. Our studies on the double layer (DL) Fe/W(110) spin spiral [2], the DL Fe/Ir(111) spin spiral [3] and the monolayer Fe/Ir(111) nano-skyrmion lattice [4] reveal the IPS local spin quantization axis rotating on the lateral atomic scale. Even high- order IPS located 10 nm away from the surface reflect the non-collinear spin texture, thereby allowing for atomic-scale magnetic imaging at unprecedented large tip-sample distances. Si |
| Date: | Tue, 12.06.2018 |
| Time: | 16:00 |
| Location: | Technische Universität Wien, Institut für Angewandte Physik, E134 yellow tower „B“, 5th floor, Sem.R. DB gelb 05 B (room number DB05L03), 1040 Wien, Wiedner Hauptstraße 8-10 |
| Contact: | Ao.Univ.Prof. Dr. W. Werner |
| Automated calculation of N-jet soft functions |
| Speaker: | Bahman Dehnadi (Univ. Siegen) |
| Abstract: | im Rahmen des Teilchenphysikseminars |
| Date: | Tue, 12.06.2018 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, H. Neufeld |
| From analytical to numerical relativity |
| Speaker: | Gernot Heißel (Vienna) |
| Abstract: | I am going to present the research I have done for my Master’s and my PhD theses.For the former, at the University of Vienna, I worked with Mark Heinzle on spatially homogenous cosmology and dynamical systems. We determined the past and future asymptotic dynamics of a particular class of models, locally rotationally symmetric Bianchi type VIII with an anisotropic fluid, and investigated the question if anisotropic matter matters. It does! For the latter, at Cardiff University and in the LIGO Scientific Collaboration, I worked with Mark Hannam on initial data for black hole simulations. I will explain what trumpet initial data is and why it is of interest, in particular with regards to binary black hole simulations for gravitational wave extraction, and how this ties in with the LSC’s task of detecting gravitational waves in the broader context. I will present our numerical approach to .. |
| Date: | Thu, 14.06.2018 |
| 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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