Contents

Idea

Nonabelian groupoid cohomology is the nonabelian cohomology of groupoids.

This generalizes nonabelian group cohomology, which is the special case of nonabelian group cohomology for groupoids that are deloopings $\mathbf{B}G$ of groups $G$.

Examples

Atiyah Lie groupoid

The Atiyah Lie groupoid $At(P) \to \Pi(X)$ of a principal bundle $P \to X$ is the extension of $\Pi(X)$ classified by the nonabelian groupoid cocycle $\Pi(X) \to \mathbf{B} AUT(G)$ coming from a connection on $P$.

Revised on January 11, 2010 23:45:35 by David Roberts (203.24.207.198)