Markus Linckelmann, City, University of London

Title: On degree -1 operators in cohomology

Abstract: We describe an elementary construction principle for operators of degree -1 on Ext-spaces of modules. We apply this to finite group cohomology, and describe in particular the BV operator on the Hochschild cohomology of a finite group algebra in terms of this construction principle. We use this to calculate the Lie algebra structure of the first Hochschild cohomology of certain finite p-group algebras. This is joint work with Radha Kessar and Dave Benson.