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Calendar of Physics Talks Vienna
| Modelling Heavy-Ion LHC Experiments as black hole collisions in AdS5 |
| Speaker: | Paul Romatschke (University of Colorado) |
| Abstract: | Nuclear Collisions may be modelled as a strong-coupling QFT problem
using the AdS/CFT correspondence. This has the advantage of being able
to follow the full dynamics of the energy-stress tensor exactly
(albeit numerically) by solving five dimensional Einstein Equations.
Performing such a calculation, including matching to hydrodynamics and
a late-stage hadronic afterburner for central nuclear collisions at
the LHC results in a almost 'parameter-free' prediction for the
particle spectra which happens to coincide with available experimental
results from ALICE. I will discuss advantages and shortcomings of the
strong coupling approach to nuclear collisions.
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| Date: | Mon, 05.05.2014 |
| Time: | 14:00 |
| Location: | Inst. f. Theoret. Physik, TU Wien, SEM136, 10.OG, Wiedner Hauptstr. 8-10 |
| Contact: | Anton Rebhan |
| Clocking the Verwey transition in magnetite: the speed limit for ultrafast switching in oxides |
| Speaker: | Mark S. GOLDEN (Van Der Waals-Zeeman Institute, Iop, University of Amsterdam) |
| Abstract: | For oxide electronics to come of age, we will need convincing that the dazzling array of physical properties transition metal oxides display can be switched on and off sufficiently rapidly. Femtosecond soft X-ray probes can clock such switching speeds, simultaneously laying bare the mechanisms at work by separating out the contributions from the lattice and electronic degrees of freedom on the time axis.
In magnetite – Fe3O4 – electrical conduction drops two-hundred-fold below Tv, as electrons freeze into a complex pattern of charge and orbitals, as first recognized by Verwey.
Harnessing the femtosecond soft X-ray pulses from the Linac Coherent Light Source, we show that for all its complexity, the charge-orbital order of the insulating Verwey phase can give way to a metallic phase in as little as a single picosecond. This not only finally solves the riddle of the how the Verwey transition works, but also sets an encouraging speed limit in our pursuit of future oxide electronics technologies.
Speed limit of the insulator-metal transition in magnetite
S. de Jong, R. Kukreja, C. Trabant, N. Pontius, C.F. Chang, T. Kachel, M. Beye, F. Sorgenfrei, C.H. Back, B. Bräuer, W.F. Schlotter, J.J. Turner, O. Krupin, M. Doehler, D. Zhu, M.A. Hossain, A.O. Scherz, D. Fausti, F. Novelli, M. Esposito, W.S. Lee, Y.D. Chuang, D.H. Lu, R.G. Moore, M. Yi, M. Trigo, P. Kirchmann, L. Patthey, M.S. Golden, M. Buchholz, P. Metcalf, F.Parmigiani, W. Wurth, A. Föhlisch, C. Schüßler-Langeheine and H.A. Dürr: Nature materials 12, 882-886 (28 July 2013)
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| Date: | Mon, 05.05.2014 |
| Time: | 17:30 |
| Location: | Universität Wien, Lise Meitner Hörsaal, Boltzmanng. 5, 1090 Wien |
| Contact: | T. Pichler |
| Euclidean QFT III - Vertex Algebras |
| Speaker: | Jan Schlemmer (Univ. Wien) |
| Abstract: | im Rahmen des Seminars für Mathematische Physik |
| Date: | Tue, 06.05.2014 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | J. Yngvason, J. Schlemmer |
| Physics and Chemistry of TiO2 Pigments – an Industrial View |
| Speaker: | Ulrich Gesenhues (Sachtleben Chemie GmbH, Duisburg/Germany) |
| Abstract: | TiO2 pigments are used worldwide for whitening paints, printing-inks, plastics and paper laminates, and for matting chemical fibers and polymer films. Some large-volume or high-value nonpigmentary applications of TiO2 are also established (DeNOx catalysts, sunscreen, wood protection). A disadvantage in pigment application is the photocatalytical activity of TiO2 which has been reduced by inorganic coats on the crystal (not part of my lecture) and by doping. I shall illustrate the practical consequences of photoactivity, present the basic understanding of the causes that has developed in the industry, and show how this can be extended with physicochemical models for bulk and surface of the TiO2 crystal.
First, the surface of TiO2, pure and with adsorbed H2O (colloidal-chemistry models, STM results and theoretical calculations from the literature), and the contributions to photoactivity f |
| Date: | Tue, 06.05.2014 |
| Time: | 16:00 |
| Location: | Technische Universität Wien, Institut für Angewandte Physik, Seminarraum 134A, Turm B (gelbe Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10 |
| Contact: | Univ.Prof. Dr. Ulrike Diebold |
| Silver Linings from Flavor Physics: The B->K*mu mu Anomaly |
| Speaker: | Javier Virto (Univ. Siegen) |
| Abstract: | im Rahmen des Teilchenphysikseminars |
| Date: | Tue, 06.05.2014 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, V. Mateu |
| Rolling without slipping or twisting. A few surprises |
| Speaker: | Pawel Nurowski (Warsaw) |
| Abstract: | im Rahmen des Literaturseminars für Gravitationsphysik |
| Date: | Thu, 08.05.2014 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
| The semi-holographic framework - applications to non-Fermi liquids and heavy ion collisions |
| Speaker: | Ayan Mukhopadhyay (Ecole Polytechnique, CPHT & IPhT, Saclay) |
| Abstract: | We will introduce the semi-holographic framework which can replace the usual effective field theories for modelling strongly interacting
systems, both at and near a critical point. In this framework, universality of physical observables in certain limits will not be important as in the traditional purely holographic models. Rather the crucial prediction will be that all phenomenological observables can be determined by finitely few parameters, whose microscopic definitions should be known in principle, although calculating them exactly will not be necessary to test the theory. A finite number of measurements can be done to fix these effective parameters, and then the remaining observables will be predicted uniquely as functions of these parameters. Using this framework, we will generalise Landau's theory to non-Fermi liquids both at zero and finite temperature. We will see that the strange metallic behaviour is far more generic than purely holographic approaches. We will also present a semi-holographic model for heavy ion collisions with three effective parameters and show that its predictions could be different from purely holographic approaches. |
| Date: | Thu, 08.05.2014 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | SEM 136 (Freihaus, Wiedner Hauptstrasse 8-10), Institute for Theoretical Physics, Vienna University of Technology |
| Contact: | Daniel Grumiller and Johanna Knapp |
| Phase transitions in the Kuramoto model |
| Speaker: | Maximilian Sadilek |
| Abstract: | im Rahmen der gemeinsam veranstalteten Seminare "Komplexe Stochastische Systeme" (Univ.Wien) und "Analyse Komplexer Systeme" (Med.Univ.Wien) |
| Date: | Fri, 09.05.2014 |
| Time: | 14:15 |
| Duration: | 90 min |
| Location: | Medizinische Univ. Wien, Informatikbibliothek, CeMSIIS; Bauteil 88, E03, Spitalgasse 23 |
| Contact: | H. Hüffel und Stefan Thurner |
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