DefinitionDefinition: Literature-sourcedProof: Not applicablejudge pass (gpt-5.6-terra)audited 2026-09-07
How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Closed immersions of schemes
Definition
A morphism is a closed immersion if its underlying map is a homeomorphism onto a closed subset and the morphism is surjective.
Depends on
Used by
- Agreement on a schematically dense open Corollary
- Degree is additive on invertible sheaves over a proper curve Corollary
- General hypersurfaces give smooth complete intersections Corollary
- Twisting the exact sequence of an effective Cartier divisor Corollary
- A proper nonprojective scheme from glued projective spaces Counterexample
- Global generation does not imply very ampleness Counterexample
- The canonical map of a hyperelliptic curve is not an embedding Counterexample
- The intersection product needs Cartier or complementary-dimension hypotheses Counterexample
- Unramified of finite presentation does not imply flat or etale Counterexample
- Algebraic cycles and the cycle group of a scheme of finite type over a field Definition
- Embedded deformations of a closed subscheme Definition
- Exceptional curves of the first kind and their contractions Definition
- Exceptional subscheme of a blowup Definition
- Formally smooth morphism Definition
- Formally unramified morphism Definition
- Hilbert function and Euler characteristic on a projective scheme Definition
- Immersion of schemes Definition
- Morphisms and closed subgroup schemes of group schemes Definition
- Morphisms, products and fibre products of algebraic spaces Definition
- Multiple test blow-ups, controlled transforms and resolutions of marked ideals Definition
- Presentations of algebraic spaces Definition
- Projective morphisms before Proj Definition
- Representable morphisms of presheaves and fibrewise properties Definition
- Scheme-theoretic image Definition
- Separated morphism of schemes Definition
- Square-zero extensions, small extensions and first-order thickenings Definition
- Strict transform of a closed subscheme Definition
- The derived subgroup, the derived series and solvable algebraic groups Definition
- Weil divisor normal noetherian scheme Definition
- A closed point immersion is unramified Example
- Additive and infinitesimal group schemes Example
- An irreducible curve can have arbitrarily large tangent dimension Example
- Incidence projection has closed determinantal image Example
- The empty morphism is finite, proper and projective Example
- Two infinitesimal structures at the origin Example
- A section of an invertible sheaf has a canonical zero subscheme Lemma
- A surjective ring map induces a closed immersion of affine spectra Lemma
- An immersion with closed image is a closed immersion Lemma
- Blowups of integral projective complex schemes are projective Lemma
- Canonical resolutions commute with embeddings of ambient smooth schemes Lemma
…and 65 more results.
Dependency tree · two levels
4 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- The Stacks Project, Morphisms of Schemes, Definition 2.1 (standard reference, not scraped)