CPT

Calendar of Physics Talks Vienna

Galilean and Carrollian limits of non-relativistic strings
Speaker:Gerben Oling (Nordita)
Abstract:I will present and analyze two novel classes of non-relativistic string actions. Non-relativistic string theory usually refers to a particular limit of string theory that results in a non-relativistic spectrum, as I will briefly review from a modern geometrical perspective. However, the worldsheet geometry of such strings is still Lorentzian. Motivated in part by decoupling limits of N=4 SYM, I will introduce two related constructions that lead to novel classes of non-relativistic strings with Galilean and Carrollian structures on the worldsheet, respectively. Time permitting, I will briefly present their Hamiltonian constraint analysis, and I will comment on their potential relevance for accessing new solvable subsectors of AdS/CFT.
Date: Tue, 21.03.2023
Time: 14:00
Duration: 60 min
Location:SEM.R.DA gruen 05 (Freihaus, TU Wien, Wiedner Hauptstrasse 8)
Contact:D. Grumiller, S. Fredenhagen, E. Battista, R. Ruzziconi

Application of energetic ion beams for nanostructuring of crystalline ZnO semiconductor
Speaker:Adéla Jagerová (Czech Academy of Science, Nuclear Physics Institute)
Abstract:Zinc oxide (ZnO) is a crystalline semiconductor used in optoelectronics, sensors or as a photocatalyst. Due to its wide direct bandgap, ZnO exhibits only UV light absorption limiting its applications. The nanostructuring of ZnO with noble metals and their nanoparticles can increase the photocatalytic activity of ZnO and enhance visible light absorption, which would extend ZnO application and improve the effectivity of ZnO-based devices. The energetic ion beams offer an interesting option for material modification. They can be used for doping of solids, defect states tailoring, preparation of metallic nanoparticles (NPs) or for the surface nanostructuring of solid materials. On the other side, ion beam modification is causing damage in implanted materials which makes ion beam modification of crystalline materials challenging. The presentation will cover the general interaction of ion beam
Date: Tue, 21.03.2023
Time: 16:00
Location:TU Wien, Institut für Angewandte Physik, E134 1040 Wien, Wiedner Hauptstraße 8-10 Yellow Tower „B“, 5th floor, SEM.R. DB gelb 05 B
Contact:Dr. Wilhelm Richard

The Hadronic Light-By-Light Contribution to the Muon g-2 in Triangle Kinematics at Short Distances
Speaker:Michael Adam (Univ. Wien)
Abstract:The Hadronic-Light-By-Light(HLbL)contribution is responsible for a significant part of the uncertainty in the present Standard Model predictionof the anomalous magnetic moment of the muon. Contributions to HLbL from the low-energy regime are determined precisely through dispersion relations for the low-lying intermediate states,while the operator product expansion and perturbative QCD provide constraints in the mixed and asymptotic regimes.How to properly match these different descriptions of HLbL is less understood and responsible for the largest part of the current uncertainty on HLbL.This thesis addresses this issue and provides the first steps towards a model-independent strategy fully based on dispersion relations to reduce uncertainties on the estimate of HLbL coming from the matching to short-distance constraints. To this end,we consider DRs for the HLbL scalar functions from ...
Date: Tue, 21.03.2023
Time: 16:15
Duration: 60 min
Location:Erwin-Schroedinger-Hoersaal, Fakultaet für Physik, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, M. Procura

On the Statistical Mechanics of a "Bar Crawl" (and an Unexpected Unification of Bosons and Fermions)
Speaker:Yuri Minoguchi (TU Wien, Atominstitut)
Abstract:A "bar crawl" is a drinking game where a group of physicists is moving through a list of bars. There is no turning back and due to communication between groups of participants in different bars, this is a complex classical many body problem. We consider two types of “crawls” with all participants equipped with one of two types of characters: “misanthropes” which like to drink alone, and “philanthropes” which like to bunch up and be on the crawl together. We show that despite their difference in character and drinking behaviour, the fluctuations of both groups are surprisingly captured by the same physics, namely the Kardar-Parisi-Zhang universality class. Despite its silliness, the example of the bar crawl is meant to highlight the crucial steps towards a hitherto unnoticed unification of bosons and fermions on a purely classical level. We conclude our discussion by contrasting it to a k
Date: Wed, 22.03.2023
Time: 16:15
Duration: 45 min
Location:Hörsaal ATI
Contact:Maximilian Prüfer

Are there gravitons? And how do you couple quantum matter to classical gravity?
Speaker:Domenico Giulini (Univ. Hannover)
Abstract:I will review some classical arguments concerning the remoteness of direct graviton detection. Treating gravity classically, the question arises how to consistently and reliably estimate the influence of classical gravitational fields on the dynamics of quantum systems. A review of the latter is given in https://arxiv.org/pdf/2207.05029.pdf
Date: Thu, 23.03.2023
Time: 15:30
Duration: 60 min
Location:on zoom https://univienna.zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09 Meeting ID: 654 003 6841 Passcode: Gs4brS
Contact:P. Chrusciel, D. Fajman

From Very Special Relativity to a gauge invariant graviton mass: gravitational waves and binary stars
Speaker:Alessandro Santoni (Chile University)
Abstract:Very Special Relativity (VSR) is a particular realization of Lorentz violation, which was presented for the first time by Cohen and Glashow in 2006 with the idea of introducing an alternative mechanism for neutrinos' masses. Since then, the ideas of VSR have been applied to many different areas. In this talk, after a short introduction to the key features of VSR, I will present its application to linearized gravity: we will see how, within the framework of VSR, it is possible to construct a coherent spin-2 free field theory, preserving the usual gauge invariance of linearized General Relativity while, at the same time, allowing for a non-zero graviton mass. Applying the geodesics' deviation equation to the VSR gravitational waves (GWs), I will give some possible estimations of the magnitude of the effects introduced by this novel theory for GWs.
Date: Thu, 23.03.2023
Time: 17:00
Duration: 60 min
Location:Freihaus, Sem.R. DB gelb 10
Contact:Iva Lovrekovic

Deterministic photon-emitter interfaces and applications in quantum-information processing
Speaker:Peter Lodahl (Niels-Bohr Institute Kopenhagen)
Abstract:Semiconductor quantum dots embedded in photonic nanostructures offer a highly efficient and coherent deterministic photon-emitter interface [1,2]. It constitutes an on-demand single-photon source for quantum-information applications, enables single-photon nonlinear optics, and the constructing of deterministic quantum gates for photons [3]. We review the fundamental operational principles of deterministic photon-emitter interfaces. We discuss the generation of photonic resource states such as high-quality single photons [4], multi-photon entanglement sources [5,6], nonlinear single-photon interaction [7], and emitter-emitter entanglement [8]. Finally, we discuss potential applications of this novel hardware for device-independent quantum key distribution [9], one-way quantum repeaters [10], and photonic quantum computing [11].
Date: Fri, 24.03.2023
Time: 10:00
Duration: 45 min
Location:ATI Hörsaal/https://tuwien.zoom.us/j/93672218922?pwd=dEZNQ2liVzRNNURvNmVWVE5KUWRiQT09
Contact:Julian Leonard