|
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 |
|