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Calendar of Physics Talks Vienna
| Matrix models of fuzzy field theories |
| Speaker: | Jurai Tekel (Comenius University Bratislava) |
| Abstract: | We introduce fuzzy field theories and give an overview of their spontaneous symmetry breaking patters. Fuzzy spaces enjoy a nontrivial short distance structure, which is reflected in some surprising ways to break the symmetry of a field theory. We then
give a description of these theories in terms of hermitian matrix models. These models are a generalization of the standard random matrix models with extra terms in the probability distribution due to the kinetic term of the field theory. We present several possible ways how to deal with this modification and show to what extent they describe the desired properties of the corresponding field theory.
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| Date: | Tue, 16.01.2018 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | TU Wien, Freihaus, SEM 136, 10. Stock, Wiedner Hauptstr. 8-10, 1040 Wien |
| Contact: | S. Fredenhagen, D. Grumiller, H. Steinacker |
| New perspectives in QCD with jet substructure |
| Speaker: | Gregory Soyez (CNRS, Paris) |
| Abstract: | im Rahmen des Teilchenphysikseminars |
| Date: | Tue, 16.01.2018 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | H. Neufeld, S. Plätzer |
| Nonlinear Interactions of Gravitational Waves |
| Speaker: | Stefan Palenta (Vienna) |
| Abstract: | After an introduction on gravitational waves and nonlinear effects in general, the talk will present the foundations of a new solution technique for the characteristic initial value problem of colliding plane gravitational waves. Assuming plane symmetry, the Einstein equations essentially reduce to the Ernst equation. In the course of the inverse scattering method this nonlinear PDE is tranlated first into an overdetermined linear system of differential equations and secondly into a Riemann-Hilbert problem. Ambiguities in this Riemann-Hilbert problem's solution lead to the construction
of families of exact spacetimes generalising the proper solution to the initial value problem. Therefore the presented technique also serves as a solution generating technique. The method is exemplified by generalising the Szekeres class of colliding plane wave spacetimes. A new type of circularly . . . . |
| Date: | Thu, 18.01.2018 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel |
| Colloquium: On the interpretation of the Top Quark Mass from Reconstruction |
| Speaker: | Prof. André Hoang (University of Vienna) |
| Abstract: | The currently most precise measurements of the top quark mass are obtained from
kinematic reconstruction obtained at hadron colliders. The observables designed to
make these measurements cannot be calculated using analytic methods in QCD and
therefore reply on multipurpose Monte-Carlo event generators. As a consequence,
the interpretation of the measured top quark masses is theoretically difficult and
still an open issue. In my talk I explain the theoretical issues inherent to this problem.
It is currently also not yet fully understood, up to a conceptual upper bound, how large
the uncertainty is when one interprets the result as measurements of the pole mass. [abridged] |
| Date: | Fri, 19.01.2018 |
| Time: | 10:30 |
| Duration: | 60 min |
| Location: | Wohllebengasse 12-14 |
| Contact: | Josef Pradler |
| Extremal CFTs with small central charge |
| Speaker: | Francesca Ferrari (Amsterdam) |
| Abstract: | In the talk I will review the different properties of 2d extremal chiral (super)conformal field theories with central charge smaller or equal to 24. These are theories whose only operators with dimension smaller or equal to c/24 are the vacuum and its Virasoro descendants. One of the most famous example is the Monster CFT. Its twining functions can be completely constructed from the vacuum structure and the modular properties of the functions via a Rademacher sum (Farey tail). Following a recent work in collaboration with Sarah Harrison, I will investigate the extent to which such a property holds for other known extremal theories. |
| Date: | Fri, 19.01.2018 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | SEM 136, TU Wien, Freihaus, 10th floor (Wiedner Hauptstr. 8-10, A-1040 Vienna) |
| Contact: | Timm Wrase |
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