Locally ringed space Created 2026-09-24 Updated 2026-09-24
A locally ringed space is a ringed space whose stalk is a local ring at every point. Morphisms of locally ringed spaces induce local homomorphisms on stalks.
Projection formula for sheaves Created 2026-09-24 Updated 2026-09-24
For a morphism of ringed spaces, there is a natural morphismIt is an isomorphism when is a locally free sheaf of finite rank, because the claim is local and then reduces to distributivity over a finite direct sum.
Pullback of a sheaf of modules Created 2026-09-24 Updated 2026-09-24
Sheaf of modules Created 2026-09-24 Updated 2026-09-24
For a ringed space , a sheaf of -modules is a sheaf such that every is an -module and restriction maps preserve scalar multiplication.
Sheaf of rings Created 2026-09-24 Updated 2026-09-24
A sheaf of rings assigns a ring to every open set, restriction homomorphisms to inclusions, and satisfies local identity and gluing. It supplies the local functions on a ringed space.