CPT

Calendar of Physics Talks Vienna

Duality defects in 2d Gauged Linear Sigma Models
Speaker:Urmi Ninad (Univ. Bonn)
Abstract:In this talk I will discuss certain 2d supersymmetric gauge theories (GLSMs) with a boundary which in the infrared flow to SCFTs that are relevant for string compactifications with D-branes. Certain non-abelian GLSMs exhibit Seiberg-like dualities which relate seemingly different ultraviolet theories with the same infrared physics. I extend the analysis of such dualities to theories with boundaries and propose the action of the duality on the boundary. I geometrically realise these boundary degrees of freedom in terms of objects in the derived category of coherent sheaves for SCFTs admitting an NLSM description and demonstrate our approach using simple examples.
Date: Tue, 29.10.2019
Time: 13:45
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:S. Fredenhagen, D. Grumiller. C. Zwikel, T. Schimannek

Kerr Primordial Black Holes: Towards New Constraints
Speaker:Jeremy Auffinger (IPNL)
Abstract:The primordial black holes solution to the dark matter issue has lately received much attention due to thenon-detection of dark matter particles (WIMPs or axions) in both direct and indirect channels. These black holes are expected to form at the very beginning of the Universe through the collapse of primordial density fluctuations. Depending on their mass distribution, they can have several observable consequences, thus allowing to set constraints on their density -- and the fraction of dark matter they can represent. The observations range from gravitational micro and femto-lensing to the emission of energetic particles through Hawking radiation. In this seminar, we will focus on the Hawking radiation constraints by extending them from the Schwarzschild primordial black holes (non-rotating) to the Kerr metric (rotating black holes) and from monochromatic [abridged]
Date: Tue, 29.10.2019
Time: 15:00
Duration: 60 min
Location:Seminar Room, Apostelgasse 23, 1030 Wien
Contact:Josef Pradler

Colour-Flow Evolution at Next-to-leading Order
Speaker:Ines Ruffa (Univ. Wien)
Abstract:im Rahmen des Seminars für Teilchenphysik: In order to investigate soft gluon evolution at NLO (next-to-leading order) the one-loop/one-emission and two-loop Feynman-diagrams have to be analysed. I will give an introduction to the colour-space formalism, and discuss the evolution equations in colour space to resum non-global observables. I will highlight the colour-flow basis as it not only provides immediate physical interpretation but it is also efficient in numerical approaches for soft gluon evolution.
Date: Tue, 29.10.2019
Time: 16:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, S. Plätzer

Probing the density tail of radioactive nuclei with antiprotons
Speaker:Prof. Alexandre Obertelli (TU Darmstadt)
Abstract:Antiprotons as a probe to study short-lived isotopes remain unexploited despite past pioneering works with stable nuclei. In particular, low-energy antiprotons offer a very unique sensitivity to the neutron and proton densities at the annihilation site, i.e. in the tail of the nuclear density. Such studies with short-lived nuclei and low-energy antiprotons are the first motivation of the proposed antiProton Unstable Matter Annihilation (PUMA) experiment. In this seminar, an overview of past nuclear structure studies with antiprotons will be given. The sensitivity to the nuclear tail of the density will be emphasised. Finally, a new project, PUMA aiming at performing antiproton annihilations onto short lived nuclei at ISOLDE, will be presented. [more details are available here: https://indico.smi.oeaw.ac.at/event/350/]
Date: Wed, 30.10.2019
Time: 17:00
Duration: 60 min
Location:Stefan-Meyer-Institut, Boltzmanngasse 3, 1090 Wien, Seminarraum 3-2-08 (2. Stock)
Contact:Prof. Dr. Eberhard Widmann, Dr. Martin Simon