|
Calendar of Physics Talks Vienna
| Logarithmic Doublets in Celestial CFT |
| Speaker: | Beniamino Valsesia (SISSA Trieste) |
| Abstract: | The AdS/CFT correspondence is a duality stating that quantum gravity in an AdS spacetime is equivalent to a conformal field theory (CFT) on its boundary. Its development has been a central topic in theoretical physics for the past 25 years. However, its extension to non-AdS backgrounds, such as flat space, remains challenging. A recent proposal suggests that 4D quantum gravity in flat space could be dual to a 2D celestial CFT on the sphere. The discovery of deep connections between Weinbergâs soft theorems and asymptotic charge conservation established a direct link between bulk soft operators and celestial CFT symmetry generators, including the stress tensor. This led to the computation of the CCFT central charge, which was found to be zero. Since a unitary CFT with vanishing central charge is trivial, alternative nontrivial CFTs must be considered. One such class is logarithmic CFTs (L |
| Date: | Tue, 11.03.2025 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | S. Fredenhagen, M. Sperling |
| Semileptonic decays at the frontier |
| Speaker: | Jack Jenkins (University of Siegen) |
| Abstract: | In this talk I will outline some of the challenges facing higher-precision extractions of CKM matrix elements and effective neutral-current couplings from inclusive B decays and rare semileptonic kaon decays, which persist despite increasingly precise perturbative information for these quantities. In the B sector, phenomenological extractions of local power correction parameters are the largest bottleneck for testing the SM with the rare mode B->X ll, and I outline an approach to scrutinize their extraction from kinematical moments of charged-current B decays. I will also discuss a dispersive approach to the nonlocal contribution to rare kaon decays K->pi ll and K->pi nu nu, and similar strategies based on chiral dynamics applied to the B -> pi form factors at high recoil. |
| Date: | Tue, 11.03.2025 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | A. Hoang, M. Procura |
| A panoramic view of low dimensional manifolds - CANCELLED!! |
| Speaker: | Willi Kepplinger (University of Vienna) |
| Abstract: | he character and status of very simple sounding questions in manifold theory depends crucially on the dimension of the manifold. An illustrative example is the famous Jordan curve theorem which roughly speaking states that a topological embedding of S^1 into R^2 separates R^2 into a bounded component (which is homeomorphic to a disk) and an unbounded one. Naively speaking this theorem seems obvious, if annoying to prove. In reality, it is a miracle it is true in the first place as corresponding statements in dimension 3 and higher are simply wrong. In this talk I will try to give an overview over questions in low dimensional topology (such as existence and uniques of smooth structures, classification of manifolds) and how these depend on the dimension. |
| Date: | Wed, 12.03.2025 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Seminar Room A, Waehringer Str. 17, 1090 Wien, 2nd floor |
| Contact: | P. Chrusciel, D. Fajman |
| Symmetries in Quantum Gravity |
| Speaker: | Markus Josef Dierigl (CERN) |
| Abstract: | Symmetries are essential in our understanding of quantum systems. In recent years the concept of symmetries has been generalized to include higher-form symmetries (acting on extended objects), higher-group symmetries (mixing various higher-form symmetries), and non-invertible symmetries (which do not satisfy a group law). In this talk I will discuss the role of generalized symmetries and their breaking at the quantum level, via anomalies, in quantum gravity. In particular, I will highlight how topological charges carried by certain spacetime backgrounds can lead us to the prediction of new dynamical objects in the fundamental theory. Moreover, I will show that demanding the absence of (generalized) anomalies in the gauge sector imposes universal consistency conditions.
|
| Date: | Thu, 13.03.2025 |
| Time: | 17:00 |
| Duration: | 60 min |
| Location: | TU Wien: Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room DB10E11 |
| Contact: | Daniel Grumiller, Ankit Aggarwal |
|