Speaker
Alexander Merkurjev
(UCLA)
Description
Let $G$ be a finite group and let M be an abelian group viewed as a $G$-module with trivial $G$-action. Fix a field $F$. A cohomology class $c$ in $H^n(G,M)$ is called negligible over $F$ if for every field extension $L/F$ and every continuous group homomorphism of the absolute Galois group of $L$ to $G$ the class $c$ belongs to the kernel of the induced homomorphism $H^n(G,M) \to H^n(L,M)$. We determine all negligible cohomology classes $c$ in $H^2(G,M)$.
This is a joint work with M.Gherman.
