CPT

Calendar of Physics Talks Vienna

Quantized cosmological constant in 1+1d gravity with scalar matter
Speaker:Simone Zonetti (CP3 - Centre for Cosmology, Particle Physics and Phenomenology Louvain-La-Neuve, Belgium)
Abstract:Considering a model of gravity in 1+1 dimensions non-minimally coupled to scalar matter I will show how the realization of quantum constraints on physical states provides a mathematical mechanism to derive the value of the cosmological constant, accounting for the quantum contributions of matter and gravity.
Date: Mon, 06.06.2011
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

Device-Independent Quantum Information Processing
Speaker:Antonio Acin (ICFO - The Institute of Photonic Sciences)
Abstract:Device-Independent Quantum Information Processing represents a new paradigm for quantum information processing: the goal is to design protocols to solve relevant information tasks without relying on any assumption on the devices used in the protocol. The main resource for device-independent quantum information processing is quantum non-locality, that is, those correlations without classical analog that can be obtained by measuring some entangled states. The talk gives an introduction to the device-independent scenario, with an emphasis on two applications: key distribution and randomness generation.
Date: Mon, 06.06.2011
Time: 17:30
Duration: 60 min
Location:Atominstitut, großer Hörsaal, Stadionallee 2, 1020 Wien
Contact:christiane.losert@univie.ac.at

Attosecond physics - Ultrafast electron dynamics in atoms
Speaker:Renate Pazourek (TU Wien)
Abstract:With the ability to control and shape infrared laser fields and the generation of isolated attosecond light pulses by high harmonic generation a new research field ? attoscience - was born about ten years ago. Since then it has become possible to study electron dynamics in atoms, molecules and solids on it's natural time scale. After a general introduction to attosecond physics I will focus on ultrafast electron dynamics in atoms, in particular correlated electron dynamics in helium for which the time-dependent Schr¿dinger equation can still be solved numerically. I will present simulations for two-photon double ionization of helium and compare some of the calculated results with experiments. In addition, I will give an introduction to attosecond streaking, a pump-probe technique using an ultrashort extreme ultaviolet pulse and a synchronized IR laser field, which allows to extract time shifts between different photoionization events with attosecond precision.
Date: Tue, 07.06.2011
Time: 12:30
Duration: 60 min
Location:Uni Wien ( Boltzmanngasse 5, 5th floor, Schrödinger HS / large seminar room )
Contact:Sabine Ertl

Computer modeling of laser-induced lesions to the eye: threshold thermal injuries in laboratory animals
Speaker:Mathieu Jean, M.Sc. (TU Wien und Seibersdorf Laboratories GmbH)
Abstract:Ocular tissues are by far the most vulnerable to optical radiation. Among various possible damage mechanisms, pure thermal damage occurs for exposures longer than approximately several µs, where the cornea and the retina are the primary targets depending on the wavelength and the spatial extent of the source. Macaque monkey and rabbit are the most suitable experimental models for the retina and the cornea, respectively. Safety guidelines and subsequent norms are up to now almost entirely supported by these expensive, time-consuming and ethically disputable experiments. A physics-based model should provide a reliable alternative. The current computerized approach basically consists of an optical model (for absorption, refraction and reflection), a thermal model solved by means of finite elements (taking conduction and convection into account) and a damage model using the Arrhenius equation for reaction kinetics. Despite experimental uncertainty and modeling inaccuracy, experimental results are reproducible within a satisfactory factor of 2.
Date: Tue, 07.06.2011
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:Ao.Univ.Prof. Dr. Wolfgang Husinsky

Graphene - why all the excitement about a single layer of graphite
Speaker:Prof. Dr. Karsten Horn (Fritz-Haber-Institut, Berlin)
Abstract:im Rahmen der Chemisch-Physikalischen Gesellschaft Within the short time span of five years, graphene, a single layer of carbon atoms arranged in a honeycomb lattice, has risen from obscurity to worldwide attention and fame, not least as a consequence of the 2010 Nobel Prize in Physics awarded to Geim and Novoselov. This intense interest is due to graphene’s unique physical properties, many of which are a consequence of its unusual electronic structure (massless “Dirac Fermion” charge carriers), requiring a description in terms of quantum electrodynamics. Graphene (“the thinnest material conceivable”) is a model system for 2-dimensional solids, and it is also interesting from a materials application perspective, since it has the potential to play an important role in technology (although this is sometimes exaggerated, at least in the popular press). It is also a boon for surface scientists, since here at last is a material that is all surface and no bulk! In the talk I will deal with the analysis of graphene’s properties on the basis of experimental data from a range of surface-related techniques. Beyond a characterization of the material itself, issues such as preparation and modification of graphene films and emerging laboratory-type applications will be briefly discussed.
Date: Tue, 07.06.2011
Time: 17:30
Location:Lise-Meitner-Hörsaal, Fakultät für Physik, Universität Wien, 1090 Wien, Strudlhofgasse 4/Boltzmanngasse 5, 1. Stock Barrierefreier Zugang: Boltzmanngasse 5, Lift, 1. Stock rechts über den Gang zum Hi
Contact:Ao.Univ.Prod. Dr. Peter Mohn

The Geometry Behind Matrix Models for 3D SUSY Gauge Theories at Large N
Speaker:Christopher P. Herzog (Princeton University)
Date: Wed, 08.06.2011
Time: 15:00
Duration: 60 min
Location:Institute for Theoretical Physics, TU Wien, SEM 136, 10th floor, Wiedner Hauptstr. 8-10, 1040 Wien
Contact:Anton Rebhan, TU Wien

Dark matter; is this really a problem?
Speaker:Prof. Donald G. Saari (Univ. of California Irvine)
Abstract:The issue concerning "dark matter" comes from Newtonian approximations for the full Newtonian N-body problem. As shown, when combined with observed rotational velocities, this approach requires mass levels that are significantly larger than what has been observed. But, is this approximation method correct? By using analytic properties of the Newtonian N-body problem to derive new relationships between rotational velocity and mass values, it is shown that the conflict is nowhere near as extreme as asserted in the literature.
Date: Thu, 09.06.2011
Time: 10:00
Duration: 60 min
Location:Arbeitsgruppe: Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock
Contact:P. T. Chrusciel

Soft and hard mesons in Chiral Perturbation Theory
Speaker:Ilaria Jemos (Univ. Lund)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Thu, 09.06.2011
Time: 14:15
Duration: 60 min
Location:Arbeitsgruppe Teilchenphysik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, H. Neufeld

Gluing of TT tensors
Speaker:Erwann Delay (Avignon)
Abstract:im Rahmen des Literaturseminars
Date: Thu, 09.06.2011
Time: 14:15
Duration: 60 min
Location:Arbeitsgruppe: Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock
Contact:P. T. Chrusciel

N=1 Vacua in N=2 Supergravity and String Theory
Speaker:Hagen Triendl (IPhT/CEA Saclay)
Abstract:We discuss N=1 vacua in spontaneously broken N=2 supergravities. We start by reviewing classical no-go theorems on their existence and how these no-go theorems can be circumvented for general N=2 supergravities. We construct stable N=1 vacua for any moduli space that might arise in type II flux compactifications and discuss quantum effects in the corresponding string theory compactifications. We also show how integrating out the massive fields leads to an N=1 effective theory at low energies and discuss to which extend moduli stabilization takes place.
Date: Thu, 09.06.2011
Time: 16:00
Duration: 90 min
Location:TU Wien, Seminar room E136
Contact:Andreas Braun

Complementarity and Which-Way Measurement
Speaker:Masanao OZAWA (Nagoya University)
Date: Fri, 10.06.2011
Time: 15:30
Location:TU Wien Atominstitut, Hörsaal, Stadionallee 2, 1020 Wien
Contact:H. Abele