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Calendar of Physics Talks Vienna
| Resurgence of topological strings |
| Speaker: | Murad Alim (TU Munich) |
| Abstract: | The partition function of topological string theory on any family of Calabi-Yau threefolds is defined perturbatively as an asymptotic series in the topological string coupling and encodes, in a holomorphic limit, higher genus Gromov-Witten as well as Gopakumar-Vafa invariants. I will prove that the partition function of topological strings of any CY in this limit can be written as a product, where each factor is given by the partition function of the resolved conifold with shifted arguments, raised to the power of certain sheaf invariants.
Using resurgence, I will show that piece-wise analytic functions in the topological string coupling can be found and that the corresponding Stokes jumps encode genus zero Gopakumar Vafa invariants. |
| Date: | Tue, 16.06.2026 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger Lecture Hall, 1090 Vienna, Boltzmanngasse 5, 5th floor |
| Contact: | S. Fredenhagen, M. Sperling |
| Surface Reconstruction and Low-Coordination Sites as Determinants of CO Reactivity on Cuprous Oxide |
| Speaker: | Jonas Weissenrieder (KTH Royal Institute of Technology, Stockholm/Sweden) |
| Abstract: | Copper-based catalysts are attractive earth-abundant materials for CO chemistry, yet the atomic-scale origins of their reactivity remain insufficiently understood. I will present results from three complementary studies that collectively establish how the catalytic behavior of cuprous oxide (Cu₂O) surfaces toward CO is governed by specific surface reconstructions and the low-coordination sites they generate. On the Cu₂O(111) surface, the nanopyramid (PY) (√3×√3)R30° reconstruction exposes coordinatively unsaturated oxygen atoms within Cu₄O clusters that are exceptionally reactive toward CO. Infrared reflection absorption spectroscopy (IRRAS) with isotopic labeling (¹³CO) confirms CO₂ formation at temperatures as low as 100 K—a rare demonstration of cryogenic reactivity for an earth-abundant metal oxide without noble-metal decoration. DFT calculations reveal a free energy barrier of only |
| Date: | Tue, 16.06.2026 |
| 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: | Prof. G. Parkinson |
| Thermodynamics of classical clocks |
| Speaker: | Patrick Pietzonka (University of Edinburgh) |
| Abstract: | In order to break the time-reversal symmetry present at thermal equilibrium, any useful clock operating autonomously in a thermal environment needs to be driven by forces that ultimately lead to the production of entropy. This poses the question whether a minimal entropic cost is necessary for a clock to be reliable. The thermodynamic uncertainty relation (TUR) states that precision of any current-like observable in a non-equilibrium steady state is related to the entropy produced in the overall system. Applied to clocks, this would mean that the squared relative uncertainty of the displayed time multiplied by the produced entropy is always greater than 2k_B.
While the TUR has been proven for Markov jump processes and overdamped Brownian diffusion, a prove for systems involving inertia remained elusive. I will show an example of a clock that exploits inertia to break the TUR. It is model |
| Date: | Thu, 18.06.2026 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Portierloge ZE, new building |
| Contact: | Paul Erker |
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