Module

ConnectedDomainStalks.lean

Nyll.SchemeTheory.LocalGeometry.ConnectedDomainStalks
1 declaration indexed from sourceView source ↗

Connected schemes with domain stalks

On a locally Noetherian scheme with domain stalks, irreducible components are open and closed. Connectedness therefore forces one component to be the whole scheme, and reducedness follows directly from the stalks.

Declarations

AlgebraicGeometry.isIntegral_of_connected_of_isDomain_stalk

A connected locally Noetherian scheme whose stalks are domains is integral.

Source context 4 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
open TopologicalSpace
namespace AlgebraicGeometry
universe u
theorem isIntegral_of_connected_of_isDomain_stalk
    (X : Scheme.{u}) [IsLocallyNoetherian X] [ConnectedSpace X]
    (hdom : ∀ x : X, IsDomain (X.presheaf.stalk x)) : IsIntegral X