ModuleDerivedLocalCohomologyTopMultiplication.lean
Nyll.EtaleFundamentalGroups.Purity.DerivedLocalCohomologyTopMultiplication
5 declarations indexed from sourceView source ↗ Module documentation
Multiplication on top maximal-support local cohomology
The coefficient map for M → M → M / xM agrees with the scalar endomorphism constructed on the ideal-powers colimit. For the ring as coefficients, a nonzero member of the maximal ideal is regular, and its quotient has zero top local cohomology by the annihilated-coefficient theorem. Exactness therefore makes multiplication by that member surjective in top degree.
Declarations
EtaleFundamentalGroups.derivedLocalCohomologyCoefficientsFirstMap_ι_apply
DocumentationThe first coefficient map acts on representatives by postcomposition with the degree-zero Ext class of the first coefficient morphism.
Source context 6 commands
Surrounding namespaces, section variables, and local commands at this declaration.
noncomputable section
open CategoryTheory Limits Opposite IsLocalRing
open scoped Pointwise
namespace EtaleFundamentalGroups
universe u
variable {R : Type u} [CommRing R]
EtaleFundamentalGroups.derivedLocalCohomologyCoefficientsFirstMap_smulShortComplex
DocumentationFor the regular multiplication short complex, the first coefficient map is the scalar endomorphism on local cohomology.
Source context 6 commands
Surrounding namespaces, section variables, and local commands at this declaration.
noncomputable section
open CategoryTheory Limits Opposite IsLocalRing
open scoped Pointwise
namespace EtaleFundamentalGroups
universe u
variable {R : Type u} [CommRing R]
EtaleFundamentalGroups.smulShortComplex_smul_id_third_eq_zero
DocumentationThe third term M / xM of the multiplication short complex is annihilated by x.
Source context 6 commands
Surrounding namespaces, section variables, and local commands at this declaration.
noncomputable section
open CategoryTheory Limits Opposite IsLocalRing
open scoped Pointwise
namespace EtaleFundamentalGroups
universe u
variable {R : Type u} [CommRing R]
EtaleFundamentalGroups.derivedLocalCohomologyScalarMap_maximalIdeal_epi_succ
DocumentationA nonzero member of the maximal ideal acts epimorphically on top maximal-support local cohomology of a Noetherian local domain.
Source context 6 commands
Surrounding namespaces, section variables, and local commands at this declaration.
noncomputable section
open CategoryTheory Limits Opposite IsLocalRing
open scoped Pointwise
namespace EtaleFundamentalGroups
universe u
variable {R : Type u} [CommRing R]
EtaleFundamentalGroups.derivedLocalCohomologyScalarMap_maximalIdeal_surjective_succ
DocumentationElementwise surjectivity of multiplication on top local cohomology.
Source context 6 commands
Surrounding namespaces, section variables, and local commands at this declaration.
noncomputable section
open CategoryTheory Limits Opposite IsLocalRing
open scoped Pointwise
namespace EtaleFundamentalGroups
universe u
variable {R : Type u} [CommRing R]