Alexandrov–Čech cohomology
E173178
Alexandrov–Čech cohomology is a topological cohomology theory that computes invariants of spaces using inverse limits over open covers, closely related to and often coinciding with sheaf cohomology.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Alexandrov–Čech cohomology canonical | 1 |
| sheaf cohomology | 1 |
| Čech cohomology | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T1509444 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
Target entity: Alexandrov–Čech cohomology Context triple: [Pavel Alexandrov, notableFor, Alexandrov–Čech cohomology]
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A.
Sheaves in Geometry and Logic
Sheaves in Geometry and Logic is a foundational monograph that develops the theory of sheaves and topos theory and explores their deep connections to geometry, logic, and the foundations of mathematics.
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B.
Poincaré duality
Poincaré duality is a fundamental theorem in algebraic topology that relates the homology and cohomology groups of an oriented closed manifold in complementary dimensions.
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C.
Categories for the Working Mathematician
Categories for the Working Mathematician is a foundational textbook in category theory that systematically develops the subject and its applications for professional mathematicians.
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D.
Whitney approximation theorem
The Whitney approximation theorem is a fundamental result in differential topology stating that any continuous function between smooth manifolds can be uniformly approximated by smooth functions.
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E.
Erlangen Program
The Erlangen Program is Felix Klein’s influential 1872 framework that classifies and studies geometries based on their underlying symmetry groups and transformation properties.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
Target entity: Alexandrov–Čech cohomology Target entity description: Alexandrov–Čech cohomology is a topological cohomology theory that computes invariants of spaces using inverse limits over open covers, closely related to and often coinciding with sheaf cohomology.
-
A.
Sheaves in Geometry and Logic
Sheaves in Geometry and Logic is a foundational monograph that develops the theory of sheaves and topos theory and explores their deep connections to geometry, logic, and the foundations of mathematics.
-
B.
Poincaré duality
Poincaré duality is a fundamental theorem in algebraic topology that relates the homology and cohomology groups of an oriented closed manifold in complementary dimensions.
-
C.
Categories for the Working Mathematician
Categories for the Working Mathematician is a foundational textbook in category theory that systematically develops the subject and its applications for professional mathematicians.
-
D.
Whitney approximation theorem
The Whitney approximation theorem is a fundamental result in differential topology stating that any continuous function between smooth manifolds can be uniformly approximated by smooth functions.
-
E.
Erlangen Program
The Erlangen Program is Felix Klein’s influential 1872 framework that classifies and studies geometries based on their underlying symmetry groups and transformation properties.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
cohomology theory
ⓘ
topological invariant ⓘ |
| alsoKnownAs |
Alexandrov–Čech cohomology
ⓘ
surface form:
Čech cohomology
|
| appliesTo |
locally contractible spaces
ⓘ
paracompact spaces ⓘ topological spaces ⓘ |
| closelyRelatedTo | Čech homology ⓘ |
| coefficientSystems |
abelian groups
ⓘ
modules ⓘ sheaves of abelian groups ⓘ |
| coincidesWith |
sheaf cohomology on paracompact spaces
ⓘ
sheaf cohomology with constant coefficients on good spaces ⓘ singular cohomology on reasonable spaces ⓘ |
| computes | cohomology groups of topological spaces ⓘ |
| constructionMethod |
direct limit over open covers
ⓘ
inverse limit over refinements of open covers ⓘ |
| definedUsing |
cochains on the nerve of an open cover
ⓘ
cocycles and coboundaries ⓘ |
| domain | topology ⓘ |
| field | algebraic topology ⓘ |
| generalizes | nerve-based computations of cohomology ⓘ |
| hasFeature |
Mayer–Vietoris sequence in de Rham cohomology
ⓘ
surface form:
Mayer–Vietoris sequence
excision property under suitable conditions ⓘ homotopy invariance under suitable hypotheses ⓘ long exact sequence of a pair ⓘ |
| historicalPeriod | 20th century mathematics ⓘ |
| namedAfter |
Eduard Čech
ⓘ
Pavel Alexandrov ⓘ |
| partOf | homological algebra in topology ⓘ |
| relatedTo |
Alexander–Spanier cohomology
ⓘ
sheaf cohomology ⓘ simplicial cohomology ⓘ singular cohomology ⓘ |
| satisfies | Eilenberg–Steenrod axioms up to mild conditions ⓘ |
| usedFor |
computing cohomology of CW complexes
ⓘ
computing cohomology of manifolds ⓘ computing sheaf cohomology ⓘ defining cohomological invariants in geometry ⓘ studying local-to-global properties of spaces ⓘ |
| uses |
cochain complexes
ⓘ
direct limits ⓘ inverse limits ⓘ nerve of an open cover ⓘ open covers ⓘ |
| usesConcept |
direct system of cochain complexes
ⓘ
inverse system of cohomology groups ⓘ refinement of covers ⓘ |
How these facts were elicited
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Subject: Alexandrov–Čech cohomology Description of subject: Alexandrov–Čech cohomology is a topological cohomology theory that computes invariants of spaces using inverse limits over open covers, closely related to and often coinciding with sheaf cohomology.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.