Calendar of Physics Talks Vienna

Adventures in the Tensionless Corner of String Theory (Vienna Theory Lunch Seminar)
Speaker: Ritankar Chatterjee (IIT Kanpur)
Abstract: Tensionless string theory is a candidate for the ultra high energy limit of string theory. In this talk I discuss some of the scenarios when a string becomes tensionless based on our earlier work. Thereafter I revisit the formulation of tensionless closed bosonic string theory following earlier works where it will be revealed that there can be three different quantum theories for tensionless strings. Afterwards I discuss our latest work where we have studied all the three quantum theories in a compactified target spacetime to study the impact of compactification on all these theories. [[part of the "Vienna Theory Lunch Seminar, see https://lunch-seminar.univie.ac.at ]]
Date: Tue, 07.11.2023
Time: 12:30
Duration: 75 min
Location:TU Wien: Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room DB10E11
Contact:Florian Lindenbauer

Anomalies, Boundaries, and Boundary States
Speaker:Dmitri Vassilevich (Universidade Federal do ABC (Brazil))
Abstract:Quantum anomalies on manifolds with boundaries naturally have boundary contributions. In CFTs, these contributions are responsible for boundary central charges, while in the condensed matter applications they define anomalous Hall conductivity of the boundary, for example. In this talk, I will describe the main properties of boundary anomalies and the methods of computations. I will show, that in some cases the anomalies on manifolds with boundaries are totally defined by anomalies in effective boundary theories. (This phenomenon is called the anomaly inflow.) I will conclude with a discussion of the relations between anomalies and boundary states.
Date: Tue, 07.11.2023
Time: 14:00
Duration: 60 min
Location:Sem. R. DB gelb 03 - TU Wien Freihaus (Wiedner Hauptstrasse 8, 3rd floor, yellow tower).
Contact:Adrien Fiorucci, Daniel Grumiller

Top quark pair production and decay with jet activity at the LHC
Speaker:Giuseppe Bevilacqua (Institute of Nuclear and Particle Physics, NCSR
Abstract:A deep theoretical understanding of $t\bar{t}$ production and decay is crucial for many measurements of top quark properties that are being carried out at the LHC.A significant fraction of $t\bar{t}$ events is accompanied by additional jet activity arising from QCD radiation. Being able to provide an accurate description of the latter is thus an important aspect of the modelling process.On top of that,precise predictions for $t\bar{t}$ + jets are key ingredients for the analysis of other important channels as well, such as $t\bar{t}H(H \to b\bar{b)}$ production at the LHC.In this talk we will address some theoretical issues of interest to accurate $t\bar{t}$ + jets calculations.The emphasis is on estimates of fiducial cross sections and on the associated uncertainties.Taking the case study of top-pair production and decay in association with two jets ($t\bar{t}jj$)we will discuss the...
Date: Tue, 07.11.2023
Time: 16:15
Duration: 60 min
Location:Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, A. Broggio, M. Procura

Constraining extended-body motion in general relativity
Speaker:Abraham Harte (Dublin City U)
Abstract:To a first approximation, objects in general relativity move along geodesics. Looked at more closely, a body's internal structure affects its motion, causing different objects to fall in different ways. This talk will explore what is possible and what is not in that context. For example, it is possible for a suitably-engineered spacecraft to change its orbit purely by changing its shape. Still, there are constraints. I will discuss how all such constraints arise from a very weak type of "local symmetry." Constraints arise from the presence of Killing vectors and from conformal Killing-Yano tensors, but from much more as well.
Date: Wed, 08.11.2023
Time: 14:15
Duration: 60 min
Location:ZOOM https://univienna.zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09
Contact:P. Chrusciel, D. Fajman

Quantum many body physics far from equilibrium from a Quantum Information point of view: Measurement induced dynamics and its breakdown via a spin-glass transition
Speaker:Yuri Minoguchi (TU Wien, Atominstitut)
Abstract:Quantum (and even classical) many body physics far from equilibrium is still a widely uncharted territory with no immediate hope for a deep underlying principle as is available in equilibrium. In a quest for a better understanding of many body dynamics, condensed matter physicists turned to quantum information. There it is common practice to classify the physics according to whether they constitute a resource to accomplish a “useful" task. Recently this program was applied to classify the dynamics of many body systems. The question there is whether some time evolution is good at hiding information from an eavesdropping third party’s measurements i.e. a good quantum errror correcting code. This line of research has become wildly popular and is sometimes also referred to by as “measurement induced dynamics”. In this talk we present our recent results on the extending this program from one
Date: Wed, 08.11.2023
Time: 16:15
Duration: 45 min
Location:Helmut Rauch Hörsaal ATI
Contact:Maximilian Prüfer

Design of an experiment for the measurement of Pontecorvo reactions
Speaker:Luca Venturelli (Universita di Brescia, INFN, Italy)
Abstract:The Pontecorvo reactions are rare antiproton annihilation processes forbidden on a free nucleon but allowed on nucleons bound in nuclei. Some measurements were performed in the past at CERN's LEAR by using deuterium target. Recently, it has been proposed [1] that the exploration of Pontecorvo reactions could be extended to CERN's ELENA-AD ring. The ASACUSA collaboration could undertake this study by utilizing a continuous beam of antiprotons, which would be directed towards targets consisting of 3 nucleons, such as 3He or 3H. The measurement of the rates of the processes... [full abstract available here: https://indico.cern.ch/event/1337891/]
Date: Wed, 08.11.2023
Time: 17:00
Duration: 60 min
Location:SMI, Postsparkasse, Georg-Coch-Platz 2, 1010 Wien, Besprechungsraum 4A.2, 4. Stock
Contact:Eberhard Widmann, Martin Simon

Quantum Systems under Drive: From Micro- to Macrophysics
Speaker:Sebastian Diehl (Universität Köln)
Abstract:Recent developments in diverse areas - ranging from cold atomic gases over light-driven semiconductors to microcavity arrays - move systems into the focus, which are located on the interface of quantum optics, many-body physics and statistical mechanics. These driven open quantum systems share in common that coherent and driven-dissipative quantum dynamics occur on an equal footing, placing them far away from thermodynamic equilibrium. We will highlight two phenomena, which witness the microscopic breaking of equilibrium conditions on a macroscopic scale, and thus do not have immediate counterparts in equilibrium many-body physics. First, we investigate the fate of the famous Kosterlitz-Thouless phase transition — a topological phase transition in two dimensions — under driving conditions. We show that an infinitesimal non-equilibrium perturbation is sufficient to suppress this transiti
Date: Fri, 10.11.2023
Time: 10:00
Duration: 45 min
Location:Helmut Rauch Hörsaal ATI
Contact:Julian Leonard