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Calendar of Physics Talks Vienna
| 'Enhancing microscopy using cavities, Pockels cells, and wave-front shaping' |
| Speaker: | Thomas Juffmann (CoQuS ) |
| Abstract: | For further information please visit https://www.coqus.at/study-program/colloquium/. |
| Date: | Mon, 18.11.2019 |
| Time: | 16:30 |
| Duration: | 120 min |
| Location: | Universität Wien, Lise Meitner Hörsaal, Strudelhofgasse 4, 1090 Wien |
| Contact: | CoQuS Administration |
| The graphical function method applied to phi^3 in D=6 |
| Speaker: | Michael Borinsky (NIKHEF, Amsterdam) |
| Abstract: | The graphical function method is an efficient tool to perform perturbative calculations
in position space QFT. One reason for this efficiency is that the method utilizes the underlying conformal properties of the QFT. I will review the method and discuss some recent extensions, in a joint work with Oliver Schnetz, of the method to arbitrary even dimensions. Using these extensions we were able calculate the 5-loop renormalization group functions in phi^3-theory. I will also discuss applications to the calculation of critical exponents in percolation theory.
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| Date: | Tue, 19.11.2019 |
| Time: | 13:45 |
| Duration: | 60 min |
| Location: | TU Wien, Wiedner Hauptstraße 8, Red Area, 7th floor, Seminar Room DC07 A15 |
| Contact: | S. Fredenhagen, D. Grumiller |
| Revolver A fast code for automated running and matching of couplings and masses in QCD |
| Speaker: | Christopher Lepenik (Univ. Wien) |
| Abstract: | In this talk I present the soon to be released software package "Revolver" which focuses on fast and precise running, matching and conversion of QCD parameters. Revolver provides an easy to use setup for renormalization group evolution with automatic matching of the QCD coupling and quark masses in the $\overline{\text{MS}}$ and MSR scheme, as well as conversion between various quark mass renormalization schemes. For most precise mass scheme conversion we implement effects originating from lighter massive quark flavors, and resum potentially large logs of characteristic scale ratios which usually appear in naive
fixed order conversion by utilizing R-evolution (IR-renormalization group flow).After reviewing some of the fundamental concepts and ideas behind quark mass renormalization schemes and R-evolution, some details of the code and its usage are discussed,including a live demo. |
| Date: | Tue, 19.11.2019 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, S. Plätzer |
| Nonlinear wave equations and the weak null condition |
| Speaker: | Joseph Keir (Oxford, UK) |
| Abstract: | im Rahmen des Literaturseminars der Gravitationsphysik:
The vacuum Einstein equations, written in "harmonic" or "wave coordinates", are
a system of nonlinear wave equations. Interestingly, very similar equations exhibit finite-time blowup, while the Einstein equations themselves admit global solutions for small initial data. The extra structure which enables them to avoid blowup is called the "weak null structure". In this talk I will explore this structure, giving a general definition and then some subclasses for which we can prove global existence for small initial data.
I will also give some details of the proof of global existence for solutions to these classes of equations.
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| Date: | Thu, 21.11.2019 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien |
| Contact: | P.T. Chrusciel, D. Fajman |
| Quasi-local conserved charges in general relativity |
| Speaker: | Henk Bart (Max Planck Institut München ) |
| Abstract: | A general prescription for constructing quasi-local conserved quantities in general relativity is proposed. The construction is applied
to BMS symmetry generators in Newman-Unti gauge, so as to define
quasi-local BMS charges. It is argued that the zero mode of this BMS
charge is a promising definition of quasi-local energy. |
| Date: | Thu, 21.11.2019 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | TU Wien, Wiedner Hauptstraße 10, Yellow Area, Seminar Room |
| Contact: | D. Grumiller, C. Zwikel |
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