Theorem of absolute purity

In algebraic geometry, the theorem of absolute (cohomological) purity is an important theorem in the theory of étale cohomology.

, the map is bijective, where the map is induced by cup product with

The theorem was introduced in SGA 5 Exposé I, § 3.1.4. as an open problem.

Later, Thomason proved it for large n and Gabber in general.

This algebraic geometry–related article is a stub.