Calendar of Physics Talks Vienna

CoQuS Colloquium Seminar Talk by Sylvain Gigan
Speaker:Sylvain Gigan (CoQuS)
Abstract:"wavefront control in disordered media: from imaging to quantum information processing" For further information please visit www.coqus.at. The details of the talk will be announced the week before the Colloquium.
Date: Mon, 27.11.2017
Time: 17:00
Duration: 90 min
Location:Lise-Meitner Hörsaal, Strudelhofgasse 4, 1090 Vienna

Spectral and dynamical properties of generalized quantum Rabi models
Speaker:Daniel Braak (Institute of Physics, University of Augsburg, Germany)
Abstract:I shall review developments in the theory of quantum Rabi models which describe the interaction between a single light mode and discrete quantum systems. The rich physics of these models in the ultrastrong and deep strong coupling region can be understood via features of the analytical solution, among them spectral collapse of the two-photon model and the hidden symmetry in the model with broken parity invariance.
Date: Tue, 28.11.2017
Time: 10:30
Duration: 60 min
Location:Semiarraum, Atominstitut, Stadionallee 2, Wien 2
Contact:P. Schneeweiß

Entanglement entropy at non-equilibrium in holography
Speaker:Daniel Fernandez (Iceland U.)
Abstract:In recent years, holographic models have proved to be successful at studying far-from-equilibrium physics. This provides a new approach to studying quantum quenches in strongly coupled systems. In this talk, based on ArXiv:1705.04696, I will focus on the local quench-like time evolution obtained by joining two 1+1 dimensional heat baths at different temperatures. I will present results for the entanglement entropy of different entangling regions obtained by adapting the time-dependent Hubeny-Rangamani-Takayanagi prescription. The interest of this study relies on the presence of emergent collective behavior, which can provide insight into the interplay between quantum effects and out of equilibrium physics.
Date: Tue, 28.11.2017
Time: 14:00
Duration: 60 min
Location:Schrodinger lecture hall (5th floor), University Vienna, Strudlhofgasse 4/Boltzmanngasse 5
Contact:Daniel Grumiller and Stefan Fredenhagen

Dark and Luminous Matter in Galaxies
Speaker:Paolo Salucci (SISSA)
Abstract:Recent observations have revealed the structural properties of the dark and luminous mass distribution in galaxies of different luminosity and Hubble Types. These results led to a new and amazing scenario. The investigation of single and coadded objects has shown that the rotation curves of spirals follow, from their centers out to their virial radii, an universal profile that implies a tuned combination of their stellar disk and dark halo mass distributions. This, alongside with accurate mass modeling of individual galaxies, poses important challenges to the ΛCDM collisionless particle. More importantly, it provides unique information on the nature of the dark particle protagonist in the structure and evolution of the Universe.
Date: Tue, 28.11.2017
Time: 14:00
Duration: 60 min
Location:HEPHY Library
Contact:Suchita Kulkarni

Dispersive analysis of pion-nucleon scattering and the pion-nucleon sigma term
Speaker:Jacobo Ruiz de Elvira (Universität Bern)
Abstract:A precise understanding of low-energy pion-nucleon interactions is central for many areas in nuclear and hadronic physics, ranging from the scalar couplings of the nucleon to the long-range part of two-pion-exchange potentials and three-nucleon forces in Chiral Effective Field Theory. We present a calculation that combines the general principles of analyticity, unitarity, and crossing symmetry with modern high- precision data of hadronic atoms, leading to a phenomenological description of the pion-nucleon amplitude with unprecedented rigor and accuracy. Consequences for the pion-nucleon sigma-term, the electromagnetic nucleon form factor and the matching to Chiral Perturbation Theory will be also discussed.
Date: Tue, 28.11.2017
Time: 16:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, H. Neufeld

Distant Worlds: the remarkable Diversity of Planets outside the Solar System
Speaker:Dr. Monika Lendl (Institut für Weltraumforschung, Österreichische Akademie der Wissenschaften)
Abstract:Planets outside the Solar System, "exoplanets", have become one of the most active research fields in Astronomy. Since the first discovery 22 years ago, more than 3000 planets are currently known to orbit stars other than our Sun. These planets and planetary systems have revealed to be remarkably different from our own Solar System, featuring highly irradiated "hot Jupiters" and low-density mini-Neptunes. Planets passing in front of their host stars as seen from Earth are Rosetta stones, as we can measure their true masses, radii and densities, as well as study their atmospheric properties. In this talk, I will review the currently known exoplanet population, and discuss implications for planet formation and evolution processes. I will highlight... [complete abstract: https://indico.smi.oeaw.ac.at/event/249/]
Date: Wed, 29.11.2017
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

On the mass of static vacuum Einstein metrics with positive cosmological constant
Speaker:Lorenzo Mazzieri (Trento)
Abstract:joint relativity-geometric analysis seminar: We introduce and discuss a notion of mass for static vacuum Einstein metrics with positive cosmological constant. In this context, we provide a positive mass statement as well as sharp area bounds for both cosmological horizons and black hole type horizons. In the first case, these area bounds represent the natural extension of a well known result by Boucher, Gibbons and Horowitz, whereas for black hole type horizons they can be seen as the analogue of the celebrated Riemannian Penrose Inequality. As an application, we deduce a uniqueness statement for the Schwarzschild--de Sitter static black hole. (Joint work with S. Borghini).
Date: Thu, 30.11.2017
Time: 14:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien
Contact:P.T. Chrusciel

Gravity, Information and the Dark Side of the Cosmos
Speaker:Erik Verlinde (University of Amsterdam)
Abstract:Im Rahmen des Vienna Seminars: In most circumstances gravity is well described by the theories of Newton and Einstein. However, there are important open questions regarding gravity at cosmological scales, especially on the nature of the observed dark matter and dark energy. At present we are witnessing a revolution in theoretical physics leading to a completely new view on space-time and gravity. Studies in string theory and black hole physics reveal a deep connection between the structure of space-time and the origin of gravity with key concepts of quantum information theory. Gravity appears as a consequence of a quantum version of the laws of thermodynamics. This means that gravity is not a fundamental force of nature, but rather an emergent phenomenon - just like temperature is an emergent phenomenon that arises from the movement of microscopic particles. . . .
Date: Thu, 30.11.2017
Time: 18:30
Duration: 90 min
Location:University of Vienna, SKY Lounge, Oskar‐Morgenstern‐Platz 1, 1090 Vienna
Contact:H. Abele, W. Grimus