Commutative algebra in stable homotopy theory and a completion theorem

Abstract

We construct a category of spectra that has all limits and col- imits and also has a strictly associative and commutative smash product. This provides the ground category for a new theory of structured ring and module spectra that allows the wholesale importation of techniques of commutative algebra into stable homotopy theory. Applications include new constructions of basic spectra, new generalized universal coefficient and Kunneth spectral sequences, and a new construction of topological Hochschild homology. The theory works equivariantly, where it allows the construction of equivariant versions of Brown-Peterson, Morava K-theory, and other module spectra over MU. Via a topological realization of local homology and cohomology the general theory leads to a com- pletion theorem for the computation of M∗(BG) and M ∗ (BG) in terms of equivariant cobordism groups, where M is MU, BP, k(n), K(n), or any other module spectrum over MU. (The reader most interested in the equivariant applications may wish to read the last section first.)