nLab
cohomology theory

Context

Cohomology

cohomology

Special and general types

Special notions

Variants

Operations

Theorems

Contents

Idea

By a cohomology theory is usually meant more precisely an example of generalized (Eilenberg-Steenrod) cohomology regarded as a functor that assigns abelian groups or even rings to topological spaces, subject to some conditions. Note that the subject of cohomology theories is itself simply called cohomology.

References