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Calendar of Physics Talks Vienna
| Initial Steps in Creating the Water-Fe3O4(111) Interface: What do we know so far, and what remains to be understood? |
| Speaker: | Dr. Joachim Paier (Humboldt Universität zu Berlin, Institut für Chemie, Berlin/Germany) |
| Abstract: | We present results obtained using density-functional theory (DFT) related approaches, such as DFT+U and Hartree-Fock/DFT hybrid functionals, combined with calorimetry and IR spectroscopy to clarify atomic-level details in initial steps of the water adsorption on the Fe3O4(111) surface. This iron oxide surface is the natural growth facet of magnetite. Thus, it represents the relevant surface exposed to water under ambient conditions.
Although, no definitive answer on the termination along the (111) direction could be given so far, the present study provides firm evidence about the creation of a very stable water dimer complex in the Fe-oct2 terminated surface. Properties of its ground-state structure obtained using PBE+U (HSE) are consistent with observed heats of adsorption and IR peaks. The latter could be unambiguously assigned to the so-called terminal OH groups of the adsorption com |
| Date: | Tue, 12.01.2016 |
| 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: | Univ.Prof. Dr. Ulrike Diebold |
| Some proposals for new physics below the GeV-scale and their implications for cosmology, astrophysics and experiment |
| Speaker: | Josef Pradler (HEPHY Wien) |
| Abstract: | im Rahmen des Teilchenphysikseminars |
| Date: | Tue, 12.01.2016 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | H. Neufeld |
| Ultra-Relativistic heavy-ion physics with ALICE at the LHC: Exploring the QCD phase diagram via the measurement of light flavor hadrons and (anti-)nuclei |
| Speaker: | Dr. Alexander Kalweit (CERN) |
| Abstract: | Thanks to its excellent particle identification performance, the ALICE experiment has measured the production yields of a complete set of light flavor hadrons in pp, p-Pb, and Pb-Pb collisions. The data spans a large dynamic range of seven orders of magnitude: from abundantly produced pions to rarely observed anti-nuclei and hyper-nuclei. Within the framework of the statistical hadronization model, the results can be related to the QCD phase boundary and chemical freeze-out parameters can be extracted. In this context, the production rates of light nuclei are particularly interesting due to their strong sensitivity on the chemical freeze-out temperature. As a an outlook, implications for the production and searches for loosely bound two body hadron molecules (such as the H-Dibaryon or potentially the X(3872)) are presented. |
| Date: | Wed, 13.01.2016 |
| Time: | 17:00 |
| Duration: | 60 min |
| Location: | Boltzmanngasse 3, 1090 Wien, Seminarraum 3-2-08 |
| Contact: | Prof. Dr. Eberhard Widmann, Dr. Martin Simon |
| On the notion of center of mass in general relativity |
| Speaker: | Anna Sakovich (Fakultät für Mathematik, Univ. Wien) |
| Abstract: | im Rahmen des Seminars in Geometric Analysis and Physics (GAP Seminar):
While the definition of center of mass via the mass density is straightforward in
Newton's theory of gravity, the situation in general relativity is more complicated. In the first
part of the talk we will discuss two approaches which can be pursued in the case of isolated
systems modeled by asymptotically Euclidean time-slices of asymptotically Minkowski
spacetimes. The first definition is derived from the Hamiltonian formalism, while the second
definition is purely geometric. In the second part of the talk we will discuss how these two
approaches extend to the case of asymptotically hyperbolic time-slices of asymptotically anti-de
Sitter spacetimes. |
| Date: | Thu, 14.01.2016 |
| Time: | 11:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock, 1090 Wien |
| Contact: | M. Bauer (Fak. Math, U.V.), V. Branding (Fak. Math, T.U.), D. Fajman (Fak. Phys, U.V.), J. Joudioux (Fak. Phys, U.V.), B. Schörkhuber (Fak. Math.,V.U.) |
| Modeling gravitational waves from neutron star mergers |
| Speaker: | Sebastiano Bernuzzi (Parma) |
| Abstract: | im Rahmen des Literaturseminars der Arbeitsgruppe Gravitation: Neutron stars mergers are among the strongest sources of gravitational waves and among the main targets for ground-based gravitational-wave interferometers Advanced LIGO and Virgo. The observation of these events in the gravitational-wave window can provide us with unique information on neutron stars' masses, radii, and spins, including the possibility to set the strongest constraints on the unknown equation-of-state of matter at supranuclear densities. However, a crucial and necessary step for gravitational-wave observations is the precise knowledge of the dynamics of the sources and of the emitted waveforms. I will talk about recent developments in the modeling of gravitational waves from neutron star mergers using numerical simulations in general relativity. |
| Date: | Thu, 14.01.2016 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
| Geometry at Infinity and Physics on the Boundary of a Space-Time |
| Speaker: | Jelle Hartong ( Brussels U. & Intl. Solvay Inst.) |
| Abstract: | Over the recent years a lot of progress has been made in extending holographic dualities (at the gravity level) to space-times that are not asymptotically AdS. Space-times such as Lifshitz, warped AdS and Schroedinger geometries (relevant for holographic applications to condensed matter systems and to Kerr/CFT) have to a greater or lesser
extent been put on a firm holographic foundation in the regime where the bulk dynamics is described by the Einstein-Hilbert action plus matter. An important role in these developments has been played by non-relativistic symmetry groups and novel types of boundary geometries such as Newton-Cartan geometries. In this talk I will first review these developments and then show that also asymptotically 3-dimensional flat space-times can be studied holographically using similar methods. I will show that the boundary geometry at future null infinity is ... |
| Date: | Thu, 14.01.2016 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | SEM 136, TU Wien, Freihaus, 10th floor (Wiedner Hauptstr. 8-10, A-1040 Vienna) |
| Contact: | Daniel Grumiller and Johanna Knapp |
| Direct probes of neutrino mass |
| Speaker: | Kathrin Valerius -Karlsruhe Institute of Technology (KIT) |
| Abstract: | This presentation gives an overview of current and future direct neutrino mass experiments. The most mature technique relies on the spectroscopy of tritium beta decay near its kinematic endpoint at 18.6 keV. The KArlsruhe TRItium Neutrino experiment (KATRIN) is targeted at improving the sensitivity of this method by an order of magnitude to 200 meV/c2 (90% C.L.). To this end, KATRIN utilises an ultra-luminous molecular gaseous tritium source and a high-resolution electrostatic spectrometer. The experiment is currently in its final construction and commissioning phase at the Karlsruhe Institute of Technology.
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| Date: | Fri, 15.01.2016 |
| Time: | 10:30 |
| Duration: | 60 min |
| Location: | HEPHY, Wohllebengasse 12-14, Seminarraum |
| Contact: | Josef Pradler |
| Neutron Scattering Studies on Chiral Multiferroics |
| Speaker: | Markus Braden (Department of Physics, University of Cologne, Germany) |
| Abstract: | Chiral magnetism plays a central role in several recently discovered phenomena such as skyrmions or type-II multiferroics. Neutron scattering with three-dimensional polarization analysis is the ideal tool to analyze chiral magnetism, because the neutron can be considered as a chiral object itself, and, therefore, such experiments can unambiguously identify chiral magnetism.
Combining unpolarized and polarized neutron scattering studies, the frequencies and polarization patterns of magnetic excitations can be precisely determined. The phason-type magnetic excitations in a cycloid are also chiral. With neutron polarization analysis we may follow this chiral character of magnons, which can be quantitatively described by spin-wave calculations.
http://solids4fun.tuwien.ac.at/sites/default/files/guest_lecture_braden.pdf
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| Date: | Fri, 15.01.2016 |
| Time: | 14:30 |
| Duration: | 45 min |
| Location: | Seminar Room CBEG02 (387, Photonics); Gußhausstraße 27 |
| Contact: | Andrei Pimenov |
| From symmetry to dynamics of quantum fields and strings |
| Speaker: | Sanjaye Ramgoolam (Queen Mary University of London) |
| Abstract: | im Rahmen des Seminars für Mathematische Physik: The long history of the study of symmetry in theoretical physics is centred on groups,
algebras and their representations. A relatively new element in this study is two
dimensional topological field theory (TFT2), which captures relations obeyed by
group theory data. I explain how TFT2 enters the construction of observables in four
dimensional conformal quantum field theory.
Conformal field theories are of particular interest in view of the AdS/CFT correspondence.
Observables in these theories contain information about strings and branes in ten dimensions
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| Date: | Fri, 15.01.2016 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | H. Steinacker |
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