Arason invariant (original) (raw)

In mathematics, the Arason invariant is a cohomological invariant associated to a quadratic form of even rank and trivial discriminant and Clifford invariant over a field k of characteristic not 2, taking values in H3(k,Z/2Z). It was introduced by (Arason , Theorem 5.7). The Rost invariant is a generalization of the Arason invariant to other algebraic groups.