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Calendar of Physics Talks Vienna
| T-witts on the soft hair program |
| Speaker: | M.M. Sheikh-Jabbari (IPM Teheran & ICTP Trieste) |
| Abstract: | im Rahmen des Joint TU/UV Theory Seminar; We study the nontrivial diffeomorphisms and the associated symmetry algebras
near a bifurcate horizon of a generic black hole.
In particular, we explore possible near horizon falloff and boundary conditions.
We discuss potential application of these analyses for the black hole microstate problem.
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| Date: | Tue, 08.10.2019 |
| Time: | 13:45 |
| Duration: | 60 min |
| Location: | TU Wien, Wiedner Hauptstraße 8, Red Area, 7th floor, Seminar Room DC07 A15 |
| Contact: | S. Fredenhagen, D. Grumiller. C. Zwikel, T. Schimannek |
| Ab initio simulation of correlated electrons: From graphene nanoribbons to warm dense matter |
| Speaker: | Michael Bonitz (Christian-Albrechts-Universität Kiel, Institut für Theoretische Physik und Astrophysik, Kiel/Germany) |
| Abstract: | The Coulomb interaction between electrons gives rise to interesting collective behavior that is manifest in
many systems around us – from astrophysics to the nanoscale. For theoretical physics, strong Coulomb
correlations are a challenge because familiar models such as ideal gas, Hartree-Fock or perturbation theory
break down. The alternative are computer simulations that have seen dramatic progress in recent years. I
will present two examples of recent work. The first are finite graphene-type structures (nanoribbons,
heterostructures) which we model using nonequilibrium Green functions. The results include the stopping
power of charged projectiles and the formation of topological edge states. The second example is „warm
dense matter“ – highly compressed and excited matter on the border between solid and plasma. Here I
outline new quantum Monte Carlo methods that have allowed us to compu |
| Date: | Tue, 08.10.2019 |
| Time: | 16:00 |
| Location: | TU Wien, Institut für Angewandte Physik, E134 1040 Wien, Wiedner Hauptstraße 8-10 Yellow Tower „B“, 5th floor, SEM.R. DB gelb 05 B |
| Contact: | Univ.Prof. Dr. Friedrich Aumayr |
| Quantum Optical Control of Levitated Solids: a novel probe for the gravity-quantum interface |
| Speaker: | Prof. Markus Aspelmeyer (Faculty of Physics, University of Vienna and Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences) |
| Abstract: | The increasing level of control over motional quantum states of massive, solid-state mechanical devices opens the door to an hitherto unexplored parameter regime of macroscopic quantum physics. I will report on our recent progress towards controlling levitated solids in the quantum regime. I will discuss the prospects of using these systems for fundamental tests of physics, including the interface between quantum and gravitational physics. |
| Date: | Tue, 08.10.2019 |
| Time: | 17:00 |
| Duration: | 60 min |
| Location: | Stefan-Meyer-Institut, Boltzmanngasse 3, 1090 Wien, Seminarraum 3-2-08 (2. Stock) |
| Contact: | Prof. Dr. Eberhard Widmann, Dr. Martin Simon |
| Relativistic Fluid Dynamics Out of Equilibrium |
| Speaker: | Paul Romatschke (University of Colorado, Boulder) |
| Abstract: | In standard textbooks, fluid dynamics is often introduced as
a near-equilibrium approximation to classical kinetic theory. Recent
advances, both in theory for out-of-equilibrium quantum field theories
and experimental data from high energy colliders, have taught us that
the textbooks are wrong: fluid dynamics quantitatively applies in
out-of-equilibrium, and highly quantum-mechanical, situations. In
these lectures, I will discuss how modern out-of-equilibrium fluid
dynamics is set up, how it relates to familiar microscopic approaches
such as kinetic theory and gauge/gravity duality, and how and when it
breaks down. If time allows, I will discuss applications of out-of-equilibrium
fluid dynamics to relativistic ion collisions at the LHC, and cosmology.
(Lecture series, continued on October 10 and 11, 2019 - see http://dkpi.at)
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| Date: | Wed, 09.10.2019 |
| Time: | 16:00 |
| Duration: | 90 min |
| Location: | TU Wien, Wiedner Haupstr. 8-10, 2nd floor, lecture hall FH HS 7 |
| Contact: | Anton Rebhan |
| Contact engineering and developments in transport theory |
| Speaker: | Guido Gandus (ETH Zürich, Switzerland) |
| Abstract: | Graphene nanoribbons (GNRs) are promising candidates for novel electronic devices: they overcome the low on/off-behavior of graphene while still preserving high charge carrier mobility that is essential for the fabrication of field effect transistors (FETs). Atomically precise GNRs can be fabricated by an on-surface synthesis approach. In this work, we characterize the transport properties of an all-carbon based device realized experimentally at EMPA. We simulate a selection of configurations to understand the relationship between the behavior of the device and its underlying atomic structure. We observe that the poor coupling between the GNR and the leads is the limiting factor in the device performance, i.e. small current modulation. Two theory-inspired designs are proposed to harvest the performance: Intercalation of adatoms prior to GNR transfer and correct alignment of GNR/graphene |
| Date: | Thu, 10.10.2019 |
| Time: | 09:00 |
| Location: | Seminar room FH gelb 09,– Vienna University of Technology, Wiedner Hauptstraße 8 – 10, 9th floor, B (yellow tower) |
| Contact: | Joachim Burgdörfer |
| HOW TO SMOOTH CRINKLES IN SPACETIME AND EXTEND UHLENBECK'S CURVATURE BOUNDS TO LORENTZIAN GEOMETRY BY THE ELLIPTIC RT-EQUATIONS |
| Speaker: | Moritz Reintjes (Konstanz) |
| Abstract: | When can you remove a singularity of spacetime by coor-dinate transformation?I will report on our recent discovery of a system of nonlinear elliptic PDE's on spacetime,the Regularity Transforma-tion equations (RT-equations),which determine whether a non-optimal connection can be smoothed to optimal regularity by coordinate trans-formation, (i.e.,to one derivative smoother than its Riemann curvature tensor Riem()).The RT-equations apply to connections on a tangent bundle TMof an arbitrary manifoldM, including semi-Riemannian and Lorentzian manifolds of Relativity.By developing an existence theory for the nonlinear RT-equations for such connections in L1,we prove that optimal connection regularity W1;p (any p < 1) can always be achieved and that no regularity singularities exist at GR shock waves.The celebrated curvature bounds of Uhlenbeck (a topic of this year's Abel prize)... |
| Date: | Thu, 10.10.2019 |
| 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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