Draft:Bivariant theory

An editor has marked this as a promising draft and requests that, should it go unedited for six months, G13 deletion be postponed, either by making a dummy/minor edit to the page, or by improving and submitting it for review.
Last edited by Calliopejen1 (talk | contribs) 7 years ago. (Update)

In mathematics, a bivariant theory, introduced by (Fulton–MacPherson 1981), is a pair of covariant and contravariant functors that assign to a map a group and a ring. It generalizes a cohomology theory, which is a contravariant functor that assigns to a space a ring, a cohomology ring. The name "bivariant" refers to "covariant" and "contravariant" nature of a theory.

Examples of bivariant theories include Chow group and algebraic K-theory.

Reference

Fulton, MacPherson, Categorical framework for the study of singular spaces, Memoirs AMS, Band 243, 1981

This geometry-related article is a stub. You can help Wikipedia by expanding it.