CPT

Calendar of Physics Talks Vienna

Gravitational waves don'ʹt go on holiday! The week of the 15th of August, 2017 seen from the perspective of the Virgo experiment
Speaker:Dr. Nicolas Arnaud (Virgo Collaboration, Laboratoire de l'ʹAccélérateur Linéaire (CNRS/IN2P3 and Université Paris-­‐‑Sud) & European Gravitational Observatory (CNRS and INFN).)
Abstract:Following a multi-year upgrade program and an intense phase of commissioning, the Advanced Virgo detector joined the two twin Advanced LIGO detectors on August 1st, 2017. During the four weeks of common data taking for the global three-detector network, promising gravitational-wave candidates were identified. Among which two discoveries which have been published last Fall: GW170814, another stellar mass binary black hole coalescence and the first signal ever seen by three gravitational-wave detectors; three days later GW170817, the first binary neutron star coalescence detected [...] The latter in particular is one of the golden events envisioned three decades ago when the LIGO and Virgo projects started being designed: it marks the beginning of the multi-messenger astronomy with gravitational waves. I will conclude... [for full abstract visit: https://indico.smi.oeaw.ac.at/event/265/]
Date: Wed, 02.05.2018
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 Teukolsky equation in Kerr spacetimes
Speaker:Siyuan Ma (MPI Potsdam-Golm)
Abstract:The Teukolsky master equation (TME) governs the dynamics of massless spin-$s$ fields in Kerr spacetime, $s=0,1,2$ corresponding to scalar field, electromagnetic field and linearized gravity respectively. In this talk, I will review the main progress on obtaining energy stimates and integrated local energy decay (Morawetz) estimates for these fields in Schwarzschild and Kerr spacetimes in the last decade, and then present the main ideas in my recent results on obtaining energy, Morawetz and pointwise decay estimates for TME in the cases of both Maxwell field and linearized gravity on Kerr backgrounds. Part of the work is joint work with Lars Andersson, Thomas Backdahl, Pieter Blue and Jinhua Wang.
Date: Thu, 03.05.2018
Time: 14:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien
Contact:P.T. Chrusciel, D. Fajman

New inflationary models in supergravity, and spontaneous supersymmetry breaking
Speaker:Prof. S. V. Ketov (Tokyo Metropolitan University and Kavli IPMU, the University of Tokyo)
Abstract:After a brief introduction to high energy physics beyond the Standard Model of elementary particles and to the Early Universe, I introduce a new class of supergravity models with spontaneous breaking of supersymmetry, capable to simultaneously describe cosmological inflation, dark energy and dark matter, together with Grand Unification of fundamental forces.
Date: Thu, 03.05.2018
Time: 16:00
Duration: 60 min
Location:TU Wien, Freihaus, SEM 136, 10. Stock, Wiedner Hauptstraße 8-10, 1040 Wien
Contact:Timm Wrase

Adsorption, Structure and Optical Properties of Organic Molecules on Surfaces
Speaker:Peter Zeppenfeld (Institute of Experimental Physics, Johannes Kepler University Linz, Austria)
Abstract:Controlling the electronic and optical properties of organic thin films is of both fundamental and technological interest. These functional properties are strongly correlated with the structural ordering and orientation of the adsorbed molecules, which can be influenced by the choice of the substrate or its preparation. I will illustrate experimental approaches to characterize and manipulate the adsorption and growth of organic thin films under well-defined conditions (ultra-high vacuum) and on atomically flat and clean substrates [1, 2]. This “surface science approach” aims at exploring the fundamental aspects of molecular self-assembly, quantifying the underlying interactions [3] and understanding the structure-property relationship [4]. Besides conventional surface science techniques, like scanning probe microscopy, surface diffraction and electron microscopy/spectroscopy, I will also introduce optical methods, namely Reflectance Difference Spectroscopy (RDS/RAS) and Differential Reflectance Spectroscopy (DRS), which can provide valuable insight into the structure and growth of ultrathin films in straight correlation with their electronic, optical and other physical or chemical properties [4, 5]. Notably, these differential optical spectroscopies can achieve sub-monolayer sensitivity and are capable of monitoring kinetic processes on surfaces in real time [6]. [1] J. Gall, P. Zeppenfeld, L. Sun, L. Zhang, Y. Luo, Z. Dong, C. Hu, P. Puschnig, Phys. Rev. B 94, 195541 (2016) [2] J. Gall, L. Zhang, X. Fu, P. Zeppenfeld, L. D. Sun, Phys. Rev. B 96, 125424 (2017) [3] L.D. Sun, J. Gall, G. Weidlinger, C.Y. Liu, M. Denk, P. Zeppenfeld, Phys. Rev. Lett. 110, 106101 (2013) [4] L.D. Sun et al., Phys. Chem. Chem. Phys. 14, 13651 (2012) [5] E. Ghanbari, Th. Wagner, P. Zeppenfeld, J. Phys. Chem. C 119, 24174 (2015) [6] R. Denk et al., Nat. Commun. 5:4253 (2014) and Nanoscale 9, 18326 (2017)
Date: Fri, 04.05.2018
Time: 15:30
Location:Hörsaal Atominstitut - Stationallee 2, 1020 Wien
Contact:A. Rauschenbeutel