The next meeting of the seminar will be held on May 16, 2014 (Friday), at 11:00, in Room 578 of the Institute of Mathematics and Informatics.

A talk on

Brauer Groups and Gerbes

will be delivered by Dr. Peter Dalakov, IMI - BAS.

Everybody is invited.

Abstract. The Picard and Brauer groups of a locally ringed space are defined as the first and second cohomology groups of the sheaf of units of the structure sheaf.

It is well known that the Picard group can be identified with the group (under tensor product) of the set of isomorphism classes of line bundles. By contrast, the Brauer group is much more subtle. In this introductory talk we are going to review some of the basic definitions related to Brauer groups (in different topologies) and will discuss some of the relations to twisted sheaves, sheaves of Azumaya algebras and gerbes. Some basic examples arising in complex geometry will be considered.