ModuleKernelBoundary.lean
Nyll.ProCGroups.CrowellExactSequence.Profinite.KernelBoundary
17 declarations indexed from sourceView source ↗ Module documentation
Boundary maps from the profinite kernel
This file constructs the completed and separated boundary maps on the kernel of a profinite presentation. It proves that these maps kill commutators and gives continuity criteria ensuring that they kill the closure of the commutator subgroup, hence factor through topological abelianization.
Declarations
CrowellExactSequence.completedKernelBoundaryProCInteger
DocumentationKernel elements map multiplicatively to the Fox completed differential module.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.separatedCompletedKernelBoundaryProCInteger
DocumentationKernel elements map multiplicatively to the separated completed differential module.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.separatedCompletedKernelBoundaryProCInteger_mem_ker_iff
DocumentationMembership in the separated completed kernel-boundary kernel is equivalent to vanishing of the corresponding finite-stage coordinate.
Source context 10 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
omit [IsTopologicalGroup G] in
CrowellExactSequence.isClosed_separatedCompletedKernelBoundaryProCInteger_ker
DocumentationThe separated kernel boundary has closed kernel, because zero can be tested at every finite stage and each finite-stage boundary is continuous.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.separatedCompletedKernelBoundaryProCInteger_commutator_le_ker
DocumentationAlgebraic part of well-definedness for the separated boundary: ordinary commutators already map to zero.
Source context 10 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
omit [IsTopologicalGroup G] in
CrowellExactSequence.separatedBoundaryKillsTopologicalCommutatorProCInteger
DocumentationThe separated kernel boundary kills \(\overline{[N,N]}\) without assuming algebraic closedness of the raw crossed-differential relation submodule.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.completedBoundaryKillsTopologicalCommutatorProCInteger_of_continuous
DocumentationIf the completed kernel boundary is continuous and its target is \(T_1\), then it vanishes on the topological closure of the kernel's commutator subgroup.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.CompletedBoundaryKillsTopologicalCommutatorProCInteger
DocumentationCorrect topological boundary factorization condition for the genuine \(N^{\mathrm{ab}}(C)\) map.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.completedBoundaryKillsTopologicalCommutatorProCInteger_of_continuousBoundary
DocumentationContinuity of the completed kernel boundary supplies the condition required for it to factor through the profinite kernel's topological abelianization.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.completedKernelBoundaryProCInteger_commutator_le_ker
DocumentationAlgebraic part of well-definedness: the kernel boundary kills the ordinary commutator subgroup of the profinite kernel. The remaining topological step is to pass from the commutator subgroup to its closure.
Source context 10 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
omit [IsTopologicalGroup G] in
CrowellExactSequence.completedBoundaryKillsTopologicalCommutatorProCInteger_of_closed_ker
DocumentationTopological form of well-definedness from closedness of the kernel of the boundary map.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.continuous_completedKernelBoundaryZC_of_continuous_zcUnivDiff
DocumentationContinuity of the universal completed differential on the ambient group implies continuity of the kernel boundary.
Source context 10 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
omit [IsTopologicalGroup G] in
CrowellExactSequence.completedBoundaryKillsTopCommZC_of_continuous_zcUnivDiff
DocumentationWell-definedness of \(d_N\) from continuity of the universal completed differential on the ambient group.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.completedBoundaryKillsTopCommZC_of_continuous_kernel_familyCoords_fintype
DocumentationFinite-coordinate form of the topological well-definedness step for \(d_N\). If a finite coordinate system on \(A_{\psi}(C)\) identifies the universal differential on the kernel with a continuous coordinate-valued map, then the ordinary commutator-killing identity extends to \(\overline{[N,N]}\). In paper language, this is the passage from a continuous coordinate formula for \(D|_N\) to the well-defined map \(N^{\mathrm{ab}}(C) \to A_{\psi}(C)\).
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.completedBoundaryKillsTopCommZC_of_continuous_kernel_familyCoords
DocumentationFin-indexed finite-coordinate form of the topological well-definedness step for \(d_N\).
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.completedBoundaryKillsTopCommZC_of_continuous_ambient_familyCoords_fintype
DocumentationFinite-coordinate ambient version of the completed-boundary theorem killing the top commutator subgroup. This is the form used when a continuous Fox-coordinate formula is constructed on the whole source and then restricted to \(\ker \psi\).
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]
CrowellExactSequence.completedBoundaryKillsTopCommZC_of_continuous_ambient_familyCoords
Documentation\(\operatorname{Fin}\)-indexed ambient-coordinate version of the completed-boundary theorem killing the top commutator subgroup for continuous kernel-family coordinates.
Source context 9 commands
Surrounding namespaces, section variables, and local commands at this declaration.
namespace CrowellExactSequence
noncomputable section
open scoped BigOperators commutatorElement
open FoxDifferential
open ProCGroups.ProC
universe u
variable {G H : Type u}
variable [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [Group H] [TopologicalSpace H] [IsTopologicalGroup H]