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Calendar of Physics Talks Vienna
| IR divergences and the effective action of supertranslation modes |
| Speaker: | Jakob Salzer (Universite Libre de Bruxelles) |
| Abstract: | Scattering amplitudes of perturbative gravity in Minkowski space suffer from well-known infrared(IR)divergences. Nevertheless,as was shown by Weinberg in a seminal paper,these IR divergencies take on a universal form such that gravity amplitudes factorize into IR-finite and IR-divergent parts.Over the course of the last decade,close connections have been uncovered between the IR behavior of scattering amplitudes of perturbative gravity and the symmetries of asymptotically flat spacetimes. These symmetries are given by the BMS group,consisting of supertranslations and superrotations. In a similar vein I will show in this talk that the above mentioned IR divergent contribution can be calculated from an effective action for the Goldstone bosons of broken supertranslations. Moreover,this action can be motivated starting from a well-defined variational principle of Einstein gravity near ...
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| Date: | Tue, 05.04.2022 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Zoom https://univienna.zoom.us/j/69976384087?pwd=dFd2NmRzMGpvS1ZSZXBKMWVPNEF5QT09 |
| Contact: | S. Fredenhagen, D. Grumiller, E. Battista, R. Ruzziconi |
| Collider Physics at the Precision Frontier: the Higgs sector under scrutiny |
| Speaker: | Gudrun Heinrich (KIT) |
| Abstract: | In the first part of the talk, we will review some recent developments
concerning precision phenomenology in the Higgs sector.
The second part will focus on Higgs boson pair production.
In particular, we will study the effects of anomalous couplings in the
Higgs sector within different variants of Effective Field Theory
descriptions.
We will illustrate how anomalous couplings could be constrained from
observables like the Higgs boson pair invariant mass spectrum. |
| Date: | Tue, 05.04.2022 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schrödinger-HS, Fakultät für Physik, Boltzmanngasse 5, 5. Stock sowie ZOOM https://univienna.zoom.us/j/93427906843?pwd=YjhSejdUVW16QjVQYUh5TVNSNFNhQT09 |
| Contact: | A. Hoang, M. Procura |
| Asymptotic symmetries at spatial infinity in higher spacetime dimensions |
| Speaker: | Javier Matulich (Université Libre de Bruxelles) |
| Abstract: | The BMS (Bondi-van der Burg-Metzner-Sachs) group was shown long ago to be the group of asymptotic symmetries of gravity in asymptotically flat spacetime. This group naturally emerges at null infinity, however, analyses at spatial infinity did not exhibit any sign of the BMS group. This discrepancy was recently resolved by considering appropriate âparity twisted boundary conditionsâ at spatial infinity leading to a full agreement with the result at null infinity. This talk will briefly describe how the infinite dimensional BMS group appears at spatial infinity in the case of Electromagnetism, General Relativity, Supergravity and the recent developments in higher spacetime dimensions.
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| Date: | Thu, 07.04.2022 |
| Time: | 16:30 |
| Duration: | 60 min |
| Location: | Freihaus, Sem.R. DB gelb 09 |
| Contact: | Iva Lovrekovic |
| Machine learning methods for high precision experiments |
| Speaker: | Max Lamparth (TU Munich) |
| Abstract: | Gaussian processes provide a framework to model physical phenomena in a Bayesian way while using little prior assumptions and being robust to overfitting [1]. We use this to model systematic corrections of high-precision experiments to improve our measurement results. This talk presents the mathematical background of Gaussian processes with physics applications for regression and Bayesian optimization [2]. We also present advanced Gaussian process models like stochastic variational Gaussian processes with further physics applications [3, 4]. Furthermore, potential applications of differential programming [5] for low energy physics experiments [6] are shown.
References
[1] C. E. Rasmussen and C. K. I. Williams, Gaussian Processes for Machine Learning, 2nd ed. (The MIT Press,2006).
[2] B. Shahriari, K. Swersky, Z. Wang, R. P. Adams, and N. de Freitas, Taking the human out of the loop: A re |
| Date: | Fri, 08.04.2022 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | https://tuwien.zoom.us/j/93672218922?pwd=dEZNQ2liVzRNNURvNmVWVE5KUWRiQT09 |
| Contact: | Hartmut Abele |
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