Calendar of Physics Talks Vienna

The Many Paths of Classicality: Bohr, Decoherence, and Classical Concepts
Speaker:Maximilian Schlosshauer (University of Copenhagen, Denmark)
Abstract:Niels Bohr famously insisted on the indispensability of what he termed "classical concepts." In the context of the decoherence program, on the other hand, it has become fashionable to talk about the "dynamical emergence of classicality" from the quantum formalism alone. Does this mean that decoherence challenges Bohr's dictum and signifies a break with the Copenhagen interpretation‐‐‐for example, that classical concepts do not need to be assumed but can be derived? In this talk I will try to shed some light down these murky waters where formalism and philosophy meet. First, I shall clarify the precise type of classicality that we deal with in the decoherence description. Then I will reflect on some of the possible notions of Bohr's classical concepts and discuss different takes on the quantum‐classical problem in Bohr's and Heisenberg's writings. Having thus laid out the different ways one might understand the term "classical" in a quantum context, I will put forward some tentative suggestions for how we may better understand the relation between decoherence‐induced classicality and Bohr's classical concepts
Date: Mon, 07.06.2010
Time: 17:30
Duration: 60 min
Location:TU Vienna, Schütte-Lihotzky-HS, HS7, Karlsplatz 13, 1040 Wien
Contact:Prof. Caslav Brukner

Conserved charges in 3D gravity
Speaker:Branislav Cvetković (Institute of Physics Belgrade)
Abstract:The covariant canonical expression for the conserved charges, proposed by Nester, is tested on several solutions in 3D gravity with or without torsion and topologically massive gravity. In each of these cases, the calculated values of energy-momentum and angular momentum are found to satisfy the first law of black hole thermodynamics. Lunch Club overview
Date: Tue, 08.06.2010
Time: 12:30
Duration: 60 min
Location:University of Vienna, Boltzmanngasse 5, 5th Floor, Large Seminar Room
Contact:David Burke, Niklas Johansson, Theodor Adaktylos, Andreas Gabriel and Christoph Spengler

Is Cosmological Dark Matter a Bose-Einstein Condensate?
Speaker:Tanja Rindler-Daller (Dept.of Astronomy & Texas Cosmology Center The Univ.of Texas at Austin) (Fakultät für Physik)
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Tue, 08.06.2010
Time: 14:15
Duration: 60 min
Location:Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:J. Yngvason

New developments in quark-gluon plasma physics
Speaker:Anton Rebhan (TU Wien) (Fakultät für Physik)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Tue, 08.06.2010
Time: 16:15
Duration: 60 min
Location:Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:H. Neufeld

Chips, Cells and Single Molecules - towards a functional understanding of the nanoscopic organization of the cellular plasma membrane
Speaker:Berufungsvortrag Biophysik: Dr. Gerhard J. Schütz (Biophysics Institute, Johannes-Kepler-Universität Linz)
Abstract:Current scientific research throughout the natural sciences aims at the exploration of the Nanocosm, the collectivity of structures with dimensions between 1 and 100nm. In the life sciences, the diversity of this Nanocosm attracts more and more researchers to the emerging field of Nanobiotechnology. In my lecture, I will show examples how to obtain insights into the organization of the cellular Nanocosm by single molecule experiments. Our primary goal is an understanding of the role of such structures for immune recognition. For this, we apply single molecule tracking to resolve the plasma membrane structure at sub-diffraction-limited length-scales by employing the high precision for localizing biomolecules of ~15nm. Brightness and single molecule colocalization analysis allows us to study stable or transient molecular associations in vivo. In particular, I will present results on the interaction between antigen-loaded MHC and the T cell receptor directly in the interface region of a T cell with a mimicry of an antigen-presenting cell. Moreover, the high sensitivity per se is of primary interest for bioanalytics. To utilize single molecule sensitivity in screening assays, we developed a scanner that enables ultra-sensitive diffraction limited recordings of biochips. We used the device for mRNA expression profiling: sample equivalents of only 10.000 cells were sufficient for robust analysis, which is two orders of magnitude below the detection limit of conventional assays. Finally, we developed a method for in vivo micropatterning of plasma membrane proteins to measure molecular interactions. This technology brings together our interest in immune signaling, and the capability for ultra-sensitive readout of large biochip surfaces. Cells transfected with a fluorescent fusion protein (“prey”) are grown on micropatterned surfaces functionalized with specific antibodies to the extracellular domain of a membrane protein (“bait”); the fluorescence copatterning is used as readout for the bait-prey interaction. We applied this technology for the study of the interaction between CD4 – the major coreceptor for T cell activation – and Lck, an important tyrosine kinase in early T cell signaling. In addition to the well-known zinc-clasp structure, we found strong contributions of Lck membrane anchorage to the binding of the two proteins.
Date: Wed, 09.06.2010
Time: 12:00
Duration: 60 min
Location:Technische Universität Wien, Institut für Angewandte Physik, Seminarraum 134, Turm B (gelbe Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Ao.Univ.Prof. Dr. Herbert Störi

The Entropy of Classical Thermodynamics
Speaker:Jakob Yngvason (Uni Wien) (Fakultät für Physik u. Medizinische Universität Wien))
Abstract:Lecture Series - Contemporary Views on Entropy in Classial, Quantum and Complex Systems
Date: Wed, 09.06.2010
Time: 16:00
Duration: 90 min
Location:Josef Stefan Hörsaal, Boltzmanngasse 5, 1090 Wien, 3. Stock
Contact:Helmuth Hüffel (Univ.Wien) Stefan Thurner (Med.Univ.Wien)

Alternative explanations of "dark energy" in cosmology
Speaker:Prof. George Ellis (Cape Town Univ.) (Fakultät für Physik)
Date: Fri, 11.06.2010
Time: 13:30
Duration: 60 min
Location:Seminarraum A, Währinger Strasse 17, 2. Stock
Contact:P.C. Aichelburg

Entropy in Many Body Quantum Systems
Speaker:Frank Verstraete (Uni Wien) (Fakultät für Physik und Medizinische Univ. Wien)
Abstract:Lecture Series: Contemporary Views on Entropy in Classical, Quantum and Complex Systems
Date: Fri, 11.06.2010
Time: 14:30
Duration: 90 min
Location:Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 1090 Wien, 5. Stock
Contact:Helmuth Hüffel und Stefan Thurner