Cohomological invariants of representations of 3-manifold groups

Haimiao Chen

Suppose $\Gamma$ is a discrete group, and $\alpha \in Z^3(B\Gamma ;A)$, with $A$ an abelian group. Given a representation $\rho :{\pi }_1(M)\to \Gamma$, with $M$ a closed 3-manifold, put $F(M,ρ)=\langle(Bρ)^\ast[…