CPT

Calendar of Physics Talks Vienna

Internal Levin-Wen models
Speaker:Vincentas Mulevicius (ESI Vienna)
Abstract:In this talk we will discuss (2+1)-dimensional topological phases of matter. In particular we will recall how they arise as degenerate ground states of lattice systems having a gapped Hamiltonian. Examples of this are the Kitaev toric code, based on a lattice of spin-1/2 particles, as well as its generalisations - the Kitaev lattice model based on Hopf algebras, and the Levin-Wen model based on fusion categories. The focus of this talk is going to be a construction allowing one to engineer a new topological order out of anyonic excitations of a given one. This construction is an analogue of the aforementioned lattice models and is best described using a universal language of topologcial quantum field theories with defects, which we will also recall.
Date: Tue, 11.10.2022
Time: 14:00
Duration: 60 min
Location: Sem.R. DB gelb 03 (Freihaus, TU Wien, Wiedner Hauptstrasse 8)
Contact:S. Fredenhagen, D. Grumiller, E. Battista, R. Ruzziconi

Magnetism in iron-rich 2D phyllosilicates
Speaker:Aleksandar Matkovic (Montanuniversität Leoben, Institute of Physics)
Abstract:Driven mainly by the potential applications in spintronics, memory, and sensing, magnetic van der Waals materials have attracted attention in the last years. While the field focuses mainly on layered iodides/tellurides and diluted layered magnetic semiconductors, the class of magnetic phyllosilicates remain almost completely unexplored. The mineral class of phyllosilicates (layered silicates) counts more than 240 members, and many of these minerals are known to incorporate local magnetic moment baring ions as Fe/Ni/Co which substitute Mg/Al sites in the central octahedral group. These naturally occurring magnetic van der Waals materials could serve as a novel and versatile platform for 2D magnetic insulators. This talk will present our recent findings on layered magnetic minerals, mainly focusing on iron-rich talc (Fe:talc) [1] and iron-micas, including their iron end-members annite, and
Date: Tue, 11.10.2022
Time: 16:00
Location:TU Wien, Institut für Angewandte Physik, E134 1040 Wien, Wiedner Hauptstraße 8-10 Yellow Tower „B“, 5th floor, SEM.R. DB gelb 05 B
Contact:Prof.G.Parkinson

Top-quark hadro-production and the top-quark mass
Speaker:Sven-Olaf MOCH (Desy, Hamburg)
Abstract:We review the current state of precision predictions for top-quark hadro-production at the Large Hadron Collider. We discuss the accuracy of perturbative corrections in quantum chromodynamics to hard scattering processes at higher orders and explore avenues for their improvements. The LHC cross section measurements are well suited for the extraction of the top-quark mass as a fundamental parameter of the Standard Model.
Date: Tue, 11.10.2022
Time: 16:15
Duration: 60 min
Location:Erwin-Schroedinger-Hoersaal, Fakultaet für Physik, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, M. Procura

Gravitational Solitons and Complete Ricci Flat Riemannian Manifolds of Infinite Topological Type
Speaker:Gilbert Weinstein (Ariel University)
Abstract:I will present several new space-periodic solutions of the static vacuum Einstein equations in higher dimensions, both with and without black holes, having Kasner asymptotics. These latter solutions are referred to as gravitational solitons. Further partially compactified solutions are also obtained by taking appropriate quotients, and the topologies are computed explicitly in terms of connected sums of products of spheres. In addition, it is shown that there is a correspondence, via Wick rotation, between the spacelike slices of the solitons and black hole solutions in one dimension less. As a corollary, the solitons give rise to complete Ricci flat Riemannian manifolds of infinite topological type and generic holonomy, in dimensions 4 and higher. This is joint work with Marcus Khuri, Martin Reiris, and Sumio Yamada.
Date: Thu, 13.10.2022
Time: 15:15
Duration: 60 min
Location:ZOOM https://univienna.zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09
Contact:P. Chrusciel, D. Fajman