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Calendar of Physics Talks Vienna
| Recent developments in non-smooth spacetime geometry (Vienna Theory Lunch Seminar) |
| Speaker: | Argam Ohanyan (University Vienna) |
| Abstract: | In Einstein's theory of General Relativity, nonsmooth phenomena naturally arise, e.g. in questions regarding the extendibility of spacetimes, geodesic singularities, or cosmic censorship. Recently, a new approach to spacetime geometry has gained significant popularity, i.e. the theory of Lorentzian length spaces. It is a new way to describe non-smooth spacetimes, and is very promising to deliver great insights, given the success of similar approaches in positive definite geometry (Alexandrov spaces, metric measure geometry, etc.). In this talk, we will introduce some of the basic notions in this theory and discuss recent progress.
[[part of the "Vienna Theory Lunch Seminar, see https://lunch-seminar.univie.ac.at ]] |
| Date: | Tue, 23.04.2024 |
| Time: | 12:30 |
| Duration: | 75 min |
| Location: | University of Vienna: Boltzmanngasse 5, 5th floor, Schrödinger Lecture Hall |
| Contact: | Florian Lindenbauer |
| Inclusive semileptonic B-meson decays and CKM matrix determinations: challenges and theoretical framework(s) |
| Speaker: | Bernat Capdevila (University of Cambridge) |
| Abstract: | The CKM matrix is a key ingredient in the study of CP violation and in New Physics searches within the flavour sector. Therefore, precise determinations of its matrix elements are of utmost importance. |Vub| and |Vcb| can be extracted from both exclusive semileptonic b â> u and b â> c decays and the inclusive channels B â> Xu l nu and B â> Xc l nu. Exclusive and inclusive determinations of these matrix elements have been in tension for a long time, with even different theoretical frameworks not agreeing well with one another. In this seminar, I am going to review some of the techniques employed in the study of inclusive semileptonic B-meson decays and present the results of our latest inclusive determination of |Vcb|. Then, I will discuss the challenges one needs to face in order to obtain a solid description for B â> Xu l nu and some of the solutions proposed. Finally, I will present th |
| Date: | Tue, 23.04.2024 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-Hoersaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Broggio |
| Static 3+1 vacuum black holes that cannot be put into stationary rotation |
| Speaker: | Martin Reiris (Montevideo) |
| Abstract: | In this talk I will show that there are vacuum static 3+1 black
hole solutions, metrically complete but non-standard spatial topology,
that cannot be put into stationary rotation. That is, there are no
non-static stationary metrics close to them. To our knowledge, this is
the first result of this kind in the literature. This is joint work
with Javier Peraza. |
| Date: | Wed, 24.04.2024 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Per zoom |
| Contact: | P. Chrusciel |
| Non-holomorphic Eisenstein Series and Quadratic Forms in Holography |
| Speaker: | Abhiram Kidambi (Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany) |
| Abstract: | Non-holomorphic Eisenstein Series are one of the simplest examples of automorphic forms (generalisations of periodic functions with some nice symmetry properties) which contain a lot of spectral and arithmetic information. In mathematics, they provide insight into important problems such as the theory of zeta functions, the Langlands program. In physics, they arise in a variety of settings in string theory (scattering amplitudes, holography of SL(2,Z) orbits of BTZ black holes) and quantum chaotic systems.
In this talk, I will go over how Eisenstein series for genus 1 surfaces series arise from normed vector spaces (Z modules or lattices) in string theory, and how they encode information of both partition functions in holography and manifold invariants of the solid torus which is of interest in holography. |
| Date: | Thu, 25.04.2024 |
| Time: | 15:00 |
| Duration: | 60 min |
| Location: | TU Wien, Freihaus, Seminar room on the 10th floor |
| Contact: | Daniel Grumiller, Iva Lovrekovic |
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