Calendar of Physics Talks Vienna

Recent developments in superstring loop amplitudes
Speaker:Oliver Schlotterer (Uppsala University)
Abstract:In this talk, I will review motivations, results and strategies for loop amplitudes in superstring theories. Based on chiral splitting of correlation functions for closed-string vertex operators, a simplified result will be presented for two-loop five-point amplitudes involving massless type-II states.
Date: Tue, 17.05.2022
Time: 14:00
Duration: 60 min
Location:Zoom https://univienna.zoom.us/j/67811513400?pwd=Y3V4VGQxZFd3aVk0VWpNNElaSVlYZz09 ID meeting: 678 1151 3400 Passcode: 634297
Contact:S. Fredenhagen, D. Grumiller, E. Battista, O. Krueger

Colour and Electroweak Evolution
Speaker:Simon Plaetzer (Univ. Graz)
Abstract:Detailed and precise predictions for high energy collisions require a deep understanding of amplitudes with many external legs, both as a basis for analytic resummation as well as for more universal event generator simulations. In a strive to improve event generators and to build numerical resummation procedures, evolution equations at the amplitude level are a universal starting point. I will discuss recent developments in QCD, with a particular focus on measurement projections and accuracy. I will then link the intricacies of this picture to electroweak amplitude factorization and sketch how a coherent framework of QCD plus electroweak evolution can be achieved.
Date: Tue, 17.05.2022
Time: 16:15
Duration: 60 min
Location:Erwin-Schroedinger-HS, Fakultaet für Physik, Boltzmanngasse 5, 5. Stock sowie ZOOM https://univienna.zoom.us/j/93427906843?pwd=YjhSejdUVW16QjVQYUh5TVNSNFNhQT09
Contact:A. Hoang, M. Procura

Bayesian parameter estimation: Integrating quantum metrology in quantum information protocols
Speaker:Simon Morelli (TU Wien Atominstitut)
Abstract:By exploiting properties intrinsic to quantum systems, quantum sensing devices hold the promise of outperforming their classical counterparts by providing a faster increase in precision with the number of probes. While much effort has been put into identifying optimal strategies, these often present substantial challenges to the actual experimental realization. We investigate a more flexible Bayesian framework for quantum metrology, allowing us to adapt to the restrictions imposed by technological limitations and facilitating the integration of estimation schemes into larger protocols. Quantum metrology plays a crucial role for noisy quantum devices, where it improves passive error correction via the estimation of unknown parameters and noise channels. In this context, we consider bosonic systems for which we identify easily implementable and robust Bayesian estimation strategies for the
Date: Wed, 18.05.2022
Time: 16:15
Duration: 45 min
Location:ATI Hörsaal/https://tuwien.zoom.us/j/93672218922?pwd=dEZNQ2liVzRNNURvNmVWVE5KUWRiQT09
Contact:Marcus Huber

Spin interaction of neutrons with an intensive laser pulse
Speaker:Christian Spreitzer (Vienna)
Abstract:We study the Dirac equation for neutral particles with a magnetic moment in the field of an ultrashort electromagnetic pulse. The pulse is modeled as a delta-distribution, concentrated on a null (i.e. lightlike) hyperplane. We show that the solutions can be obtained by "gluing" free solutions along the pulse and derive corresponding matching conditions. For the special case of a homogeneous electromagnetic pulse, i.e. constant field strength, we explicitly calculate the change in the spin orientation. This is joint work with Peter C. Aichelburg and Herbert Balasin.
Date: Thu, 19.05.2022
Time: 15:00
Duration: 60 min
Location:Gravitationsphysik, Seminarraum A - Währinger Strasse 17, 2. Stock - ZOOM https://univienna.zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09
Contact:P. Chrusciel, D. Fajman

Quantum dynamics in strongly correlated one dimensional Bose gases
Speaker:Manuele Landini (Innsbuck University)
Abstract:I will report on our recent observation of impurity dynamics in a strongly interacting 1D Bose gases. Employing an optical lattices and a Feschbach resonance, we are able to reach Lieb-Liniger interaction parameters close to 100. We generate impurities by coupling on average one atom per 1D tube to a different Zeeman level. An overlapping resonance allows for tuning of the interactions between the impurity and the Bulk. Launching the impurity at different velocities inside the 1D system, below and above the speed of sound, we observe the ensuing dynamics. In the strongly interacting Tonks-Girardeau limit, a Newton's cradle behaviour is observed with sudden stopping of the impurity (on the time scale of the Fermi time) and ejection of particles from the bulk of the system.
Date: Fri, 20.05.2022
Time: 10:00
Duration: 45 min
Location:ATI Hörsaal/https://tuwien.zoom.us/j/93672218922?pwd=dEZNQ2liVzRNNURvNmVWVE5KUWRiQT09
Contact:Julian Leonard