Cartier divisor

E860118

A Cartier divisor is a type of divisor on an algebraic variety defined locally by a single rational function, corresponding to an invertible sheaf and generalizing the notion of a principal divisor.

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Statements (49)

Predicate Object
instanceOf Weil divisor generalization
divisor in algebraic geometry
geometric object
appearsIn EGA II NERFINISHED
Hartshorne Algebraic Geometry NERFINISHED
associatedTo rational map to projective space via complete linear system
canBeEffective yes
canBePulledBackAlong morphism of schemes
canBeViewedAs global section of the sheaf of Cartier divisors
correspondsTo invertible sheaf
line bundle
definedLocallyBy single rational function
definedOn algebraic variety
scheme
defines Cartier class in Picard group
determines invertible sheaf O_X(D)
effectiveIf locally given by regular function
forms abelian group under addition
generalizes principal divisor
groupDenotedBy Div(X)
hasLocalEquation nonzero rational function
hasOperation linear equivalence
hasPoleLocus subscheme defined by poles of local equations
hasSheafTheoreticDescription invertible subsheaf of K_X
hasSubgroup group of principal divisors
hasZeroLocus subscheme defined by vanishing of local equations
isDeterminedBy invertible sheaf up to linear equivalence
isEquivalentTo invertible subsheaf of the sheaf of total quotient rings
isLocallyPrincipal yes
isReflexive under dualization of associated line bundle
isSectionOf sheaf of total quotient rings modulo units
linearlyEquivalentIf difference is principal divisor
lineBundleAssociation O_X(D)
mayNotCoincideWith Weil divisor on singular variety
namedAfter Pierre Cartier NERFINISHED
onNormalVariety determines Weil divisor
onRegularScheme equivalent to Weil divisor
onSmoothVariety same as Weil divisor
principalSubgroupDenotedBy Prin(X)
pullbackWellDefinedIf morphism is flat or divisor is Cartier
quotientByPrincipalDivisors Picard group NERFINISHED
relatedTo Picard group Pic(X) NERFINISHED
restrictsTo Cartier divisor on open subscheme
supports closed subset of codimension at least 1
usedFor construction of linear systems
definition of canonical divisor
definition of line bundles
intersection theory
study of projective embeddings

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.

Weil divisor relatedTo Cartier divisor