Guest lectures and seminars - Page 174

Gunther Cornelissen, Utrecht University (The Netherlands) will give a talk with title "Dynamical systems and point counting"

Abstract: Counting the points of a curve over finite fields doesn't determine the curve up to isomorphism; this is analogous to the famous fact that you cannot "hear the shape of a drum". I will show how to remedy this by counting points in a weighted way (namely, using abelian L-series). The method of proof is through the theory of dynamical systems, and - curiously - arose from a study of a quantum statistical mechanical system.  

Makoto Yamashita, p.t. University of Copenhagen, will give a talk with title "Tannaka-Krein duality of quantum homogeneous spaces"

Abstract: We study ergodic actions of compact quantum groups on operator algebras  (quantum homogeneous spaces) from the categorical point of view. The language of Rep(G)-module C*-categories gives a reconstruction theorem of quantum homogeneous spaces, which also captures the equivariant Morita equivalence and the equivariant homomorphisms.  For the case of quantum SU(2), the universality of Rep(SUq(2)) allows us to obtain a combinatorial description of quantum homogeneous spaces and their properties. Based on joint work with Kenny De Commer (arXiv:1211.6552, arXiv:1212.3413).  

Rama Cont (Imperial College) holder et seminar med tittelen: Functional Ito calculus and functional Kolmogorov equations

Magnus Dahler Norling, UiO, will give a talk with title: The K-theory of some reduced inverse semigroup C*-algebras

Abstract: We use a recent result by Cuntz, Echterhoff and Li about the K-theory of certain reduced C*-crossed products to describe the K-theory of C*_r(S) when S is an inverse semigroup satisfying certain requirements. A result of Milan and Steinberg allows us to show that C*_r(S) is Morita equivalent to a crossed product of the type handled by Cuntz, Echterhoff and Li. We apply the results to graph inverse semigroups and the inverse semigroups of one-dimensional tilings.