CPT

Calendar of Physics Talks Vienna

Analysing the optical nonlinearity of a cavity-like subwavelength atomic array (Vienna Theory Lunch Seminar)
Speaker:Simon Panyella Pedersen (TU Wien)
Abstract: Sub-wavelength arrays of quantum emitters offer an interesting approach to coherent light-matter interfacing, using ultracold atoms or two-dimensional solid-state quantum materials. The combination of collectively suppressed photon-losses and emerging optical nonlinearities due to strong photon-coupling to mesoscopic numbers of emitters holds promise for generating nonclassical light and engineering effective interactions between freely propagating photons. In my talk I will describe the interaction between photons and a specific configuration of two-level atoms, namely two parallel 2D arrays individually acting like mirrors and together forming a cavity-like system. [[... full abstract https://lunch-seminar.univie.ac.at ]]
Date: Tue, 18.06.2024
Time: 12:30
Duration: 75 min
Location:TU Wien: Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room DB10E11
Contact:Florian Lindenbauer

Fuzzy de Sitter spaces in three and four dimensions
Speaker:Ilija Buric (University of Pisa)
Abstract:We discuss noncommutative (anti) de Sitter spaces in two, three and four dimensions. After recalling their definitions, we analyse coordinate spectra, coherent states, invariant vacua and eigenfunctions of the Laplace-Beltrami operator. Our results pave the way for the analysis of late time correlation functions in QFTs on fuzzy dS backgrounds, of potential relevance for inflationary cosmology. The talk is based on joint works with Bojana Brkić, Maja Burić and Duško Latas.
Date: Tue, 18.06.2024
Time: 14:00
Duration: 60 min
Location:TU Wien Freihaus, Wiedner Hauptstrasse 8, 3rd floor, yellow tower, Sem. R. DB gelb 03
Contact:S. Fredenhagen, D. Grumiller, T. Tran, A. Fiorucci

Small Schwarzschild de Sitter black holes, quantum extremal surfaces and islands
Speaker:Kaberi Goswami (Chennai Mathematical Institute (CMI))
Abstract: In arxiv: 2312.05604 we have studied 4-dimensional Schwarzschild de Sitter black holes in the regime where the black hole mass is small compared with the de Sitter scale, following arXiv:2207.10724 [hep-th]. The de Sitter temperature is very low compared with that of the black hole. We consider the future boundary as the location where the black hole Hawking radiation is collected. Using 2-dimensional tools, we find unbounded growth of the entanglement entropy of radiation as the radiation region approaches the entire future boundary. Self-consistently including appropriate late time islands emerging just inside the black hole horizon leads to a reasonable Page curve. We also discuss other potential island solutions which show inconsistencies.
Date: Thu, 20.06.2024
Time: 15:00
Duration: 60 min
Location:TU Wien, Freihaus, Seminar room on the 10th floor
Contact:Daniel Grumiller, Iva Lovrekovic