|
Calendar of Physics Talks Vienna
| Higher idempotent completions and TQFTs |
| Speaker: | Markus Zetto (University of Hamburg) |
| Abstract: | “Condensation" is a mechanism for producing new topological quantum field theories from existing ones. Gaiotto and Johnson-Freyd have proposed a higher-categorical description of condensation in terms of higher idempotents, generalizing familiar concepts such as idempotent operators and separable algebras to defects of arbitrary codimensions.
In this talk, I will give a conceptual picture of their idea and explain how higher idempotent completions and variants can be used to construct and classify framed fully extended TQFTs. Based on joint work in progress with David Reutter.
|
| Date: | Tue, 09.06.2026 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | S. Fredenhagen, M. Sperling |
| From filament interactions to large-scale mechanics: a validated hydrodynamic theory of crosslinked cytoskeletal networks and its applications |
| Speaker: | Jakob R. Schindelwig (TU Wien, IAP, FB Biophysik) |
| Abstract: | The cytoskeleton — a network of biopolymer filaments crosslinked by motor proteins — generates the forces that drive cell division, motility, and morphogenesis. Despite decades of study, no quantitative framework exists that
derives the large-scale material behavior of these networks analytically from filament-level crosslinker interaction rules and validates the result: continuum theories leave their coefficients as phenomenological parameters, while particle-based simulations reproduce experimental observations without yielding analytic constitutive relations.
Here we close this gap. Starting from filament-level interaction rules, we derive a hydrodynamic field theory of highly crosslinked networks in which every material coefficient is given by an explicit analytic expression in terms of the filament-level crosslinker arclength-moment parameters $C_{mn}& and $\sigma_{mn}$ — with no fr |
| Date: | Tue, 09.06.2026 |
| 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: | Sebastian Fürthauer |
| Generalised anomalies, QCD, and holography |
| Speaker: | Shigeki Sugimoto (Kyoto University) |
| Abstract: | During the last decade, the notion of an 't Hooft anomaly has been generalised to the case of discrete symmetries. An interesting instance, discussed by Tanizaki, is the mixed anomaly between the discrete axial symmetry and the flavour and baryonic symmetries in massless QCD4. The goal of this note is to provide a derivation of this anomaly from a top-down holographic dual of QCD4. It is found that the topological couplings in the bulk supergravity dual of the D4-D8 system encode Tanizaki's anomaly, once fluctuations around the bulk gauge fields are turned on. A technical challenge for this computation is the difficulty in maintaining gauge invariance of supergravity theories in the presence of D-branes. To overcome this issue, a compact formulation of the flux sector of (massive) type IIA supergravity in the presence of D8 branes is presented. |
| Date: | Wed, 10.06.2026 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | TU Wien, Wiedner Hauptstrasse 8-10, seminar room, yellow tower, 10th floor |
| Contact: | Anton Rebhan |
| Spectroscopy of Hadrons at the COMPASS and Belle (II) Experiments |
| Speaker: | Dr Stefan Wallner (Max Planck Institute for Physics, Garching) |
| Abstract: | Quark confinement in hadrons is a well-established phenomenon. However, a complete quantitative understanding of the principles governing the quark configurations realized in nature remains elusive. To address this, we study the excitation spectra of baryons and mesons, including searches for exotic states that defy the rules of the quark model. We present results from the Belle and Belle II experiments, utilizing the worldâs largest dataset of e+eâ collisions recorded at and around the Î¥(nS ) resonances. We report on heavy-meson decays, the first search for exotic pentaquarks in inclusive Î¥(1S ,2S ) decays, and precision studies of light mesons in Ï-lepton decays.
Complementary, we discuss the strange-meson spectrum studied at the COMPASS experiment via diffractive scattering of a high-energy kaon beam. For details see https://indico.global/event/16954/ |
| Date: | Thu, 11.06.2026 |
| Time: | 10:00 |
| Duration: | 60 min |
| Location: | Marietta Blau Institute for Particle Physics, Dominikanerbastei 16 [PSK], 1010 Vienna, Besprechungsraum 3A.1/2 |
| Contact: | Claude Amsler, Ulyana Dupletsa |
| Probing Fundamental Physics with Radioactive Molecules |
| Speaker: | Ronald Fernando Garcia Ruiz (Massachusetts Institute of Technology, Cambridge) |
| Abstract: | Rapid advances in the control and interrogation of individual atoms and molecules are opening new avenues for probing the properties of fundamental particles and their interactions. In particular, molecules containing heavy, radioactive nuclei with reflection-asymmetric shapes provide exceptional sensitivity to parity- and time-reversal-violating nuclear effects. Precision measurements in these systems therefore offer a powerful approach to addressing major open questions in fundamental physics, including the origin of the matterâantimatter asymmetry of the universe, the strong CP problem, and the possible existence of physics beyond the Standard Model. In this seminar, I will present recent results and future directions in precision studies of these exotic systems, with a focus on radium-containing molecules. I will discuss how such molecules are emerging as a compelling new frontier in |
| Date: | Fri, 12.06.2026 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | Tim Langen |
|