Author: Peter Webb
Address:
School of Mathematics,
University of Minnesota,
Minneapolis MN 55455

Title:
Resolutions, Relation Modules and Schur Multipliers for Categories

Abstract:
We show that the construction in group cohomology of the Gruenberg resolution 
associated to a free presentation and the resulting relation module can be 
copied in the context of representations of categories. We establish 
five-term exact sequences in the cohomology of categories and go on to show 
that the Schur multiplier of the category has properties which generalize 
those of the Schur multiplier of a group.

Preprint November 2007.

This paper was announced in the Oberwolfach report, 
'The low-dimensional cohomology of categories'.