Calendar of Physics Talks Vienna

Unimodular quantum cosmology
Speaker:Natascha Riahi (Vienna)
Abstract:Lunchseminar: I will discuss the steps of quantization of a simple cosmological model. Starting with the unimodular version of General Relativity the result will be an evolving wave function. There is no need for the commonly used frozen time formalism.
Date: Mon, 29.06.2015
Time: 13:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, common room, 1. Stock
Contact:P.T. Chrusciel

The influence of coherence effects on inelastic electron scattering
Speaker:Dipl.-Ing. Walid Hetaba (TU Wien, Universitäre Service Einrichtung für Transmissions-Elektronenmikroskopie (USTEM) und Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin/D)
Abstract:Electron energy loss spectrometry (EELS) in the transmission electron microscope (TEM) is used to investigate not only the chemical composition of a sample but also the electronic structure. Furthermore, interference effects in the TEM give rise to a number of powerful techniques. Combined with electron channelling (energy losses by channelled electrons, ELCE), investigations can be performed in a site-specific manner. This was applied to Rutile in order to investigate the bonding situation and the atomic orbitals. Another powerful technique presented in this talk is energy-loss magnetic chiral dichroism (EMCD), which allows the investigation of the sample’s magnetic properties. It was used to perform in-situ measurements on Heusler-alloys, which show a magneto-caloric effect related to a structural transformation. Furthermore, the change in magnetic moments due to the Verwey transition
Date: Tue, 30.06.2015
Time: 16:00
Location:Technische Universität Wien, Institut für Angewandte Physik, E134 yellow tower „B“, 5th floor, Seminarraum 134A (room number DB05L03) 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Ao.Univ.Prof. Dr. Herbert Störi

Gamma-ray searches for WIMP Dark Matter with the Fermi LAT: A Rhapsody in Blue
Speaker:Christoph Weniger (GRAPPA, University of Amsterdam)
Abstract:Despite the enormous success of astrophysical and cosmological research over the last decades, about 85% of the matter content in the Universe remains unknown. The currently leading hypothesis for this so-called dark matter are Weakly Interacting Massive Particles (WIMPs). Currently, indirect searches for self-annihilation products of these WIMPs in gamma rays are of particular interest, since high-precision data from the Fermi Large Area Telescope (LAT) allows for the first time the detailed study of a large number of promising targets, from the inner Galaxy to dwarf spheroidal galaxies and the extragalactic gamma-ray background. However, with increasing sensitivity it becomes also more and more challenging to understand astrophysical foregrounds with the required accuracy. I will give here an overview over the history, status and possible fate of the most interesting signatures and
Date: Thu, 02.07.2015
Time: 14:00
Duration: 60 min
Location:Library, Institute of High Energy Physics (HEPHY), Nikolsdorfer Gasse 18, 1050 Wien
Contact:Josef Pradler