N-fold Cech derived functors and generalised Hopf type formulas, by Guram Donadze, Nick Inassaridze, and Timothy Porter

In 1988, Brown and Ellis published a generalised Hopf formula for the higher homology of a group. Although substantially correct, their result lacks one necessary condition. We give here a counterexample to the result without that condition. The main aim of this paper is, however, to generalise this corrected result to derive formulae of Hopf type for the n-fold Cech derived functors of the lower central series functors Z_k. The paper ends with an application to algebraic K-theory.

Guram Donadze <donad@rmi.acnet.ge>
Nick Inassaridze <inas@rmi.acnet.ge>
Timothy Porter <t.porter@bangor.ac.uk>