Kervaire semi-characteristic
In mathematics, the Kervaire semi-characteristic, introduced by, is an invariant of closed manifolds M of dimension taking values in, given by
showed that the Kervaire semi-characteristic of a differentiable manifold is given by the index of a skew-adjoint elliptic operator.
Assuming M is oriented, the Atiyah vanishing theorem states that if M has two linearly independent vector fields, then.
