Events for 02/12/2016 from all calendars

Mathematical Physics and Harmonic Analysis Seminar

Time: 1:50PM - 2:50PM

Location: BLOC 628

Speaker: Dale Frymark, Baylor U.

Title: Iterated Rank-One Perturbations and the Absence of Extended States

Abstract: We construct an Anderson-type Hamiltonian in its spectral representation via the iterative introduction of rank one perturbations. We remain in control of the expected value for the total mass of the resulting operators' absolutely continuous part. This is ongoing work with Constanze Liaw and Alex Poltoratski.

Linear Analysis Seminar

Time: 2:00PM - 3:00PM

Location: BLOC 220

Speaker: Pawel Kasprzak, University of Warsaw

Title: Closed quantum subgroups, open quantum subgroups and integrable actions of locally compact quantum groups

Abstract: I will overview the theory of closed quantum subgroups and open quantum subgroups. In particular the concept of closed quantum subgroups in the sense of Woronowicz and in the sense of Vaes will be introduced and related. (Joint work with Daws, Skalski and Sołtan.) Then the class of open quantum subgroups will be defined and characterised. The quantum counterpart of Bekka et al result and Rieffel result on the embedding of the quantum group C*-algebras will be presented. (Joint work with Kalantar and Skalski.) Finally I will relate the concept of integrable actions with the concept of closed and open quantum subgroups. In particular I will present the result saying that a closed quantum subgroup in the sense of Woronowicz is closed in the sense of Vaes iff the corresponding action of the​ quantum ​ subgroup on the algebra of bounded measurable functions on the​ quantum ​ group is integrable. (Joint work with Khosravi and Sołtan).

Algebra and Combinatorics Seminar

Time: 3:00PM - 4:00PM

Location: BLOC 628

Speaker: Sarah Witherspoon, Texas A&M University

Title: A Tale of Two Constructions in Hochschild Cohomology

Abstract: Modules for a ring can be strung together with maps between them to form an "extension". For some rings, equivalence classes of extensions may be taken as a definition of Hochschild cohomology, and collectively, extensions of the same length form a category which can be viewed topologically. In this introductory talk, we will give definitions, explain two constructions of a graded Lie bracket on Hochschild cohomology (one topological and one algebraic), and mention some examples.

Linear Analysis Seminar

Time: 4:00PM - 5:00PM

Location: BLOC 220

Speaker: Roland Vergnioux, Université de Caen Basse-Normandie

Title: The radial MASA in free orthogonal quantum groups

Abstract: In a recent joint work with Amaury Freslon, we prove that the subalgebra generated by the fundamental character in a free orthogonal quantum group factor is maximal abelian and mixing, and we compute the associated measure class. I will recall the construction of these objects and present the main ideas of the proof by using the analogy with the radial MASA in free group factors.