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Calendar of Physics Talks Vienna
| Propagators in curved spacetimes from operator theory |
| Speaker: | Christian Gass (University of Vienna) |
| Abstract: | I will present two distinct operator-theoretic settings, which are useful for describing (or defining) propagators associated with a scalar Klein-Gordon field on a Lorentzian manifold M. The first setting is based on the Hilbert space of square integrable functions on M and leads to the definition of an "operator-theoretic Feynman propagator". The second setting is based on the Krein space of solutions of the Klein-Gordon equation and leads to a rigorous definition of two-point functions associated to two (possibly different) states. When M admits a reasonable definition of "out" and "in" states, the operator-theoretic Feynman propagator from the first setup typically corresponds to the time-ordered two-point function from the "in" to the "out" state in the second setup. After a general introduction, I will discuss several examples -- the one with the richest structure being de Sitter sp |
| Date: | Tue, 26.11.2024 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-Hoersaal, 1090 Vienna, Boltzmanngasse 5, 5th floor |
| Contact: | S. Fredenhagen, M. Sperling |
| Modification and analysis of materials by MeV ions |
| Speaker: | Gyula Nagy (TU Wien, IAP, FB Atom- und Plasmaphysik) |
| Abstract: | I will talk about two distinct topics on which I actively worked during the last few years. One of these topics is the patterned structuring of materials by micro-focused ion beams with applications in the fields of micro-optics and micro-fluidics. I will discuss the design process of our micro-components, such as diffraction gratings and cell capture devices, their realization by grayscale lithography, and then their characterization and functionality test. The second topic is materials analysis by ion micro- and macro-beams, with applications in thin film physics, medical research, and materials chemistry. In conjunction with this topic, I will present our recent methodological developments that enable the quantification of elemental concentration depth gradients by Rutherford backscattering spectrometry. I will also discuss the applications of these developments i) to the calculation |
| Date: | Tue, 26.11.2024 |
| Time: | 16:00 |
| Location: | TU Wien, Institut für Angewandte Physik, E134 1040 Wien, Wiedner HauptstraÃe 8-10 Yellow Tower âBâ, 5th floor, SEM.R. DB gelb 05 B |
| Contact: | Prof. Dr. Richard WILHELM |
| Frontiers in Table Top Quantum Gravity |
| Speaker: | Marios Christodoulou (IQOQI Vienna) |
| Abstract: | Table Top Quantum Gravity nowadays colloquially refers to a forming interdisciplinary field that includes diverse contributions from theorists, experimentalists and philosophers alike across a range of disciplines from spacetime physics to quantum technologies. I discuss some of my contributions to the debate surrounding this nascent research field, while giving an overview of recent ideas and foundational issues that have arisen. |
| Date: | Wed, 27.11.2024 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Seminarraum A, Waehringer Strasse 17, 2nd Floor |
| Contact: | Piotr T. Chrusciel, David Fajman |
| Friday Seminar TU Wien Atominstitut |
| Speaker: | Thomas Pohl (TU Wien) |
| Abstract: | folgt |
| Date: | Fri, 29.11.2024 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Helmut Rauch Lecture Hall |
| Contact: | Julian Leonard |
| Cooperative optics in dipolar quantum materials |
| Speaker: | Thomas Pohl (Technische Universität Wien, Institute for Theoretical Physics) |
| Abstract: | Expanding our ability to generate and manipulate quantum states of light via effective photon-photon interactions has long been a central goal of optics and quantum science and may be considered an enabling step for technological applications. Since photons hardly interact in vacuum, quantum nonlinear effects require a strong coupling between light and matter, which is typically achieved with optical resonators. Conversely, structured arrangements of individual quantum emitters have recently attracted interest as promising optical interfaces in free space, with high-level control over collective photon scattering to enable strong and coherent light-matter coupling.
This talk will present different realizations of such settings based on ultracold atoms and solid-state materials. Here, the combination of concepts from both fields can yield ideas to realize and analyse optical nonlinearit |
| Date: | Fri, 29.11.2024 |
| Time: | 10:00 |
| Location: | Atomistitut, Helmut Rauch Hörsaal, Stadionallee 2, 1020 Wien |
| Contact: | Julian Léonard |
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