About: G-spectrum

In algebraic topology, a G-spectrum is a spectrum with an action of a (finite) group. Let X be a spectrum with an action of a finite group G. The important notion is that of the homotopy fixed point set . There is always a map from the fixed point spectrum to a homotopy fixed point spectrum (because, by definition, is the mapping spectrum .) Example: acts on the complex K-theory KU by taking the conjugate bundle of a complex vector bundle. Then , the real K-theory. The cofiber of is called the of X.