Calendar of Physics Talks Vienna

CoQuS Colloquium Seminar Talk by Thibaut Sylvestre
Speaker:Thibaut Sylvestre (CoQuS)
Abstract:Surface Brillouin scattering in optical microfibers Brillouin light scattering in optical fibres is a fundamental interaction between light and sound with important implications ranging from optical sensors to slow and fast light. In conventional optical fibres, light both excites and feels shear and longitudinal bulk elastic waves, giving rise to forward-guided acoustic wave Brillouin scattering and backward-stimulated Brillouin scattering. Here we demonstrate a new type of Brillouin scattering from surface acoustic waves in both tapered and photonic crystal microfibers. This effect may prove interesting for applications to optical sensing that can exploit surface acoustic waves, or for precise metrology of optical micro and nanofibers.
Date: Mon, 03.04.2017
Time: 17:00
Duration: 90 min
Location:Atominstitut, Stadionallee 2, 1020 Vienna
Contact:CoQuS Team

Covariant Quantum Spaces, Matrix Models and Gravity
Speaker:Harold Steinacker (Univ. Wien)
Abstract:I will discuss geometrical properties and physical perspectives of 4-dimensional covariant quantum spaces, focusing on the fuzzy 4-sphere. These spaces realize quantum geometries with local and global symmetries. The fluctuations on such a background within the IKKT matrix model lead to a higher spin theory, due to the underlying twisted bundle structure. Some aspects of the gravitational sector are elaborated, and the linearized Einstein equations modified by an IR cutoff are extracted under some assumptions.
Date: Tue, 04.04.2017
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:S. Fredenhagen, H. Steinacker

Investigation of noise barrier sound reflection properties
Speaker:Paul Reiter MSc (AIT Austrian Institute of Technology & TU Wien, IAP)
Abstract:Traffic noise from roads and railways is not only a daily annoyance for many people, it can also cause severe health problems. Therefore, noise protection is an important task of modern mobility infrastructure. One of the main measures against traffic noise are noise barriers, which are subject to several measurement standards for their evaluation. These measurement standards allow the investigation of relevant parameters, such as sound transmission, sound reflection and sound diffraction over the top edge of a noise barrier. In recent years, in-situ measurement methods have been developed that can be applied directly on the assembled barrier. This presentation gives an overview on noise barrier design and functionality. Porous absorbers are introduced as novel components of noise barriers. With regard to noise barrier modelling, the way from a simple plane wave acoustic model to a comp
Date: Tue, 04.04.2017
Time: 16:00
Location:Technische Universität Wien, Institut für Angewandte Physik, E134 yellow tower „B“, 5th floor, Sem.R. DB gelb 05 B (room number DB05L03), 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Ao.Univ.Prof. Dr. Martin Gröschl

The MSR Mass and the ℴ(ΛQCD) Renormalon Sum Rule
Speaker:Christopher Lepenik (Univ. Wien)
Abstract:im Rahmen des Teilchenphysik-Seminars
Date: Tue, 04.04.2017
Time: 16:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, H. Neufeld

Log Calabi--Yau compactifications of Landau--Ginzburg models
Speaker:Dr. Victor Przyjalkowski (Steklov Institute, Moscow)
Date: Thu, 06.04.2017
Time: 11:00
Duration: 60 min
Location:ESI, Boltzmann Lecture Hall

Non-peeling spacetimes
Speaker:Juan Valiente-Kroon (Queen Mary)
Abstract:In this talk I will give an overview of Friedrich’s construction of a regular asymptotic initial value problem at spatial infinity and the open questions related to it. In particular, I will show how this framework can be used to identify initial data sets for the vacuum Einstein field equations which should lead to spacetimes not satisfying the peeling behaviour. This is research in collaboration with Edgar Gasperin.
Date: Thu, 06.04.2017
Time: 14:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien
Contact:P.T. Chrusciel

Universal corrections to entanglement entropy of local quantum quenches and scrambling time
Speaker:Surbhi Khetrapal (Centre for High Energy Physics, Indian Institute of Science)
Abstract:We study the time evolution of single interval Renyi and entanglement entropies following local quantum quenches in 2d CFTs at finite temperature for which the locally excited states have a finite temporal width, epsilon. We show that, for local quenches produced by the action of a conformal primary field, the time dependence of Renyi and entanglement entropies at order epsilon^2 is universal. It is determined by the expectation value of the stress tensor in the replica geometry and proportional to the conformal dimension of the primary field generating the local excitation. We also show that in CFTs with a gravity dual, the epsilon^2 correction to the holographic entanglement entropy following a local quench precisely agrees with the CFT prediction. We compute another correction when the CFT has higher spin chemical potential, and find that its time dependence is universal. ...
Date: Thu, 06.04.2017
Time: 16:00
Duration: 60 min
Location:SEM 136, TU Wien, Freihaus, 10th floor (Wiedner Hauptstr. 8-10, A-1040 Vienna)
Contact:Daniel Grumiller and Johanna Knapp

Tales from spring brakes
Speaker:Jorge Alegre Cebollada (National Center for Cardiovascular Research Madrid, Spain)
Abstract:The heart is a mechanical machine that has little room for failure. Differently to pumps manufactured by men, the heart is built upon soft tissue. What are the mechanical properties of cardiac tissue and its constituent proteins sustaining the remarkable activity of the heart? How is the elasticity of the myocardium tuned to accommodate the expansion of the ventricles during diastole? How do mutations in proteins with a mechanical role trigger the development of life-­‐threatening cardiomyopathies? Since the mechanical properties of proteins are not accessible to standard bulk biochemical techniques, our lab takes a multidisciplinary approach to try to answer all these questions. We specialize in single molecule methods using atomic force microscopy (AFM), which are able to measure the effects of mechanical forces on proteins. We focus on titin and cardiac myosin binding protein C, two k
Date: Fri, 07.04.2017
Time: 10:00
Location:Seminarraum Lehar 02, Lehartrakt BC, 2nd floor TU Wien, Getreidemarkt 9, 1060 Vienna
Contact:Univ.Prof. Dr. G. Schütz