Equivariant Poincare Duality on G-Manifolds - Equivariant Gysin Morphism and Equivariant Euler Classes

It also makes it possible to replace the usual field of coefficients for cohomology, the field of real numbers, with any field of arbitrary characteristic, and hence change (equivariant) de Rham cohomology to the usual singular (equivariant) cohomology .