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Calendar of Physics Talks Vienna
| Higher-Spin Gravity in Three-Dimensional Flat Space (Vienna Theory Lunch Seminar) |
| Speaker: | Philipp Neckam (TU Wien) |
| Abstract: | Theories of interacting massless fields of spin larger than two naturally emerge in the high-energy limit of string theory. When including gravity, these theories also serve as toy models to investigate the holographic AdS/CFT correspondence in a more controlled setting. While it has long been known that the existence of such theories is strongly restricted by various no go theorems, in three dimensions none of these results apply, thus providing an ideal setting to study higher-spin gravity. Even so, the investigation of three-dimensional metric-like higher-spin gravity theories has been initiated only recently in 2018, and the work discussed here is a continuation of these efforts. The Noether-procedure is generalized to three dimensions, taking into account the influence of dimension-dependent-identities. [ full abstract and more information: https://lunch-seminar.univie.ac.at ] |
| Date: | Tue, 14.01.2025 |
| Time: | 12:15 |
| Duration: | 75 min |
| Location: | TU Wien: Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room DB10E11 |
| Contact: | Florian Lindenbauer |
| Topological features in lattice models |
| Speaker: | Vincentas Mulevicius (University of Vienna) |
| Abstract: | In this talk I will give an introduction to simple lattice systems having topological properties, in particular the Kitaev's toric code and its generalisations - the Levin-Wen models. Using these models as an example we will also discuss topological phases of matter and how they are related with quantum memory, quantum computing and topological quantum field theories.
If time permits, I will also describe the role of non-invertible symmetries in these models and how they can be used to `engineer' new topological phases out of a given one.
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| Date: | Tue, 14.01.2025 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | S. Fredenhagen, M. Sperling |
| The quality/cosmology tension for a post-inflationary QCD axion |
| Speaker: | Zhiquan Sun (MIT) |
| Abstract: | It is difficult to construct a post-inflation QCD axion model that solves the axion quality problem (and hence the Strong CP problem) without introducing a cosmological disaster. Firstly, generic solutions to the quality problem complicates the solution to the cosmological domain wall problem, leading to a cosmology where domain walls dominate the energy density of the universe. Secondly, post-inflation axion models also face a potential problem from fractionally charged relics; solving this problem often leads to low-energy Landau poles for Standard Model gauge couplings, reintroducing the quality problem. We study several examples, finding that models that solve the quality problem face cosmological problems, and vice versa. Successful examples may have a nonstandard cosmological history, undermining the widespread expectation that the post-inflation QCD axion scenario predicts a uniqu |
| Date: | Tue, 14.01.2025 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | A. Hoang, M. Procura |
| Probing gluon saturation via diffractive jet production in photon-nucleus interactions |
| Speaker: | Edmond IANCU (IPhT, Saclay) |
| Abstract: | Hadronic interactions at high energy are controlled by a dense form of partonic matter, known as the Colour Glass Condensate (CGC), which is mostly made with gluons and whose main characteristic is the phenomenon of gluon saturation: the gluon occupation numbers are large, of order $1/\alpha_s$, but they cannot grow any further, due to strong mutual repulsion. Given its high density, this gluon matter is weakly coupled, which opens the way to first principles calculations of hadronic cross-sections. Yet, despite an accumulation of data (at HERA, RHIC and the LHC) which are globally consistent with expectations from the CGC, the onset of saturation â which occurs in a limited window of transverse momenta â has never been directly observed. We propose a new process which is particularly promising in that sense: the diffractive production of jets in high-energy hadronic interactions... |
| Date: | Thu, 16.01.2025 |
| Time: | 16:00 |
| Location: | TU Wien Freihaus (Wiedner HauptstraÃe 8-10), Sem.R. DB gelb 05 A |
| Contact: | Markus Leuthner |
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