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Calendar of Physics Talks Vienna
| 2+1d Topological Phases and the F-symbol |
| Speaker: | Matthew Buican (Queen Mary University London) |
| Abstract: | The classification of topological phases of matter in 2+1d is notoriously difficult. At a physical level, much of the difficulty lies in getting a handle on the braiding data of anyonic excitations as well in characterising the associativity data of the anyonic OPE (i.e., the so-called âF-symbolsâ). Recently there has been great progress in characterising anyon braiding. In this talk, I will describe progress toward constraining the associativity data. |
| Date: | Tue, 26.05.2026 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | S. Fredenhagen, M. Sperling |
| Spin-2 resonances in the Hadronic Light-by-Light contribution to the muon g-2 |
| Speaker: | Emilis Kaziukenas (University of Vienna) |
| Abstract: | The muon anomaly (also known as g-2) is one of the most precisely known quantities in all of Physics. The comparison between its recent measurements from the E989 experiment at Fermilab and the Standard Model prediction from the Muon g-2 Theory Collaboration shows that the presence of a New Physics signature in this observable is inconclusive. A faithful comparison with the experiment requires reducing theoretical uncertainties by a factor of 4, which, at current precision, is dominated by two non-perturbative hadronic contributions: the Hadronic Vacuum Polarization (HVP) and the Hadronic Light-by-Light (HLbL) scattering.
One of the leading sources of uncertainty in the HLbL contribution to the muon g-2 is the tower of spin-2 resonances, beginning with the f_2 (1270). We present progress in evaluating these effects within a new dispersive framework in triangle kinematics |
| Date: | Tue, 26.05.2026 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | A. Hoang, M. Procura, J. Pradler |
| Complete asymptotics and localized formation of quiescent big bang singularities |
| Speaker: | Andres Franco-Grisales (KTH Royal Institute of Technology, Stockholm) |
| Abstract: | I will present two recent results on big bang singularities. First, there is a general condition on initial data for the Einstein-nonlinear scalar field equations which ensures that the corresponding development has a quiescent big bang singularity to the past of a point. This result can be seen as a localization of the big bang formation result of Oude Groeniger, Petersen and Ringström. Second, I will discuss how to obtain complete asymptotics for a large class of solutions to the Einstein-nonlinear scalar field equations with quiescent big bang singularities, by showing that they induce geometric initial data on the singularity. The first result is achieved by introducing a new gauge for Einstein's equations, which is fully hyperbolic and compatible with the second result. This is based on joint work with Hans Ringström. |
| Date: | Wed, 27.05.2026 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Seminar Room A, Waehringer Str. 17, 1090 Wien, 2nd floor |
| Contact: | D. Fajman |
| The uncertainty geometry of finite-dimensional position and momentum |
| Speaker: | Dimpi Thakuria (Atominstitut, TU Wien) |
| Abstract: | The covariance matrix provides a comprehensive characterization of quantum fluctuations and correlations, capturing geometric and operational features of quantum states that go far beyond individual variances or standard uncertainty relations. In this work, we characterize the covariance matrices attainable for a finite-dimensional pair of observables, namely those related by the discrete Fourier transform, which serves as the natural analogue of position and momentum in a finite Hilbert space. Using a combination of analytic methods, convex geometry, and semi-definite programming techniques based on joint numerical ranges, we describe the admissible uncertainty region in terms of unitary invariants such as the trace and determinant of the covariance matrix. This framework allows us to identify extremal quantum states, extending the notion of minimum-uncertainty states to the discrete se |
| Date: | Wed, 27.05.2026 |
| Time: | 16:15 |
| Duration: | 45 min |
| Location: | Atominstitut, Helmut Rauch Hörsaal |
| Contact: | Elena Redchenko |
| Speaker: | Frederica Surace (Trinity College Dublin) |
| Abstract: | folgt |
| Date: | Fri, 29.05.2026 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | VCQ Nadine Hilmar |
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