CW complexes
E911364
CW complexes are topological spaces built by inductively attaching cells of increasing dimension, providing a flexible and combinatorially tractable framework for algebraic topology.
All labels observed (1)
| Label | Occurrences |
|---|---|
| CW complexes canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T11219611 — 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: CW complexes Context triple: [Characteristic Classes, hasSubject, CW complexes]
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A.
Eilenberg–MacLane spaces
Eilenberg–MacLane spaces are topological spaces characterized by having a single nontrivial homotopy group, serving as fundamental building blocks in homotopy theory and the definition of cohomology.
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B.
Eilenberg–Steenrod axioms
The Eilenberg–Steenrod axioms are a foundational set of conditions that formally characterize homology theories in algebraic topology.
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C.
Alexandrov–Čech cohomology
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.
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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.
Alexander–Spanier cohomology
Alexander–Spanier cohomology is a cohomology theory in algebraic topology defined using cochains on all finite subsets of a space, notable for its generality and close relationship to Čech and singular cohomology.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
Target entity: CW complexes Target entity description: CW complexes are topological spaces built by inductively attaching cells of increasing dimension, providing a flexible and combinatorially tractable framework for algebraic topology.
-
A.
Eilenberg–MacLane spaces
Eilenberg–MacLane spaces are topological spaces characterized by having a single nontrivial homotopy group, serving as fundamental building blocks in homotopy theory and the definition of cohomology.
-
B.
Eilenberg–Steenrod axioms
The Eilenberg–Steenrod axioms are a foundational set of conditions that formally characterize homology theories in algebraic topology.
-
C.
Alexandrov–Čech cohomology
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.
-
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.
Alexander–Spanier cohomology
Alexander–Spanier cohomology is a cohomology theory in algebraic topology defined using cochains on all finite subsets of a space, notable for its generality and close relationship to Čech and singular cohomology.
- F. None of above. chosen
Statements (50)
| Predicate | Object |
|---|---|
| instanceOf |
mathematical structure
ⓘ
topological space ⓘ |
| exampleOf | cell complex ⓘ |
| field | algebraic topology NERFINISHED ⓘ |
| generalizes |
finite cell complexes
ⓘ
simplicial complexes ⓘ |
| hasProperty |
0-skeleton is a discrete set of points
ⓘ
Hausdorff NERFINISHED ⓘ admits CW-structure on many familiar spaces ⓘ admits cellular approximation of maps ⓘ attaching maps determine the CW structure ⓘ built from open cells ⓘ built inductively by attaching cells ⓘ cellular chain complex computes homology ⓘ cellular cochain complex computes cohomology ⓘ closed under homotopy equivalence up to CW-approximation ⓘ closure-finite condition on cells ⓘ combinatorially tractable ⓘ constructed by attaching n-dimensional cells ⓘ countable CW complexes have countably many cells ⓘ each cell attached via continuous map from boundary sphere ⓘ every CW complex is weakly homotopy equivalent to a simplicial complex under mild conditions ⓘ finite CW complexes have finitely many cells ⓘ flexible for constructions in topology ⓘ good for computing homotopy type ⓘ has a filtration by skeleta ⓘ locally finite in many applications ⓘ n-skeleton is obtained by attaching n-cells to (n-1)-skeleton ⓘ subcomplexes are unions of cells ⓘ supports Whitehead theorem for CW complexes ⓘ supports cellular approximation theorem ⓘ supports obstruction theory ⓘ weak topology condition on closures of cells ⓘ weak topology with respect to its cells ⓘ well-behaved with respect to homotopy ⓘ |
| introducedBy | J. H. C. Whitehead NERFINISHED ⓘ |
| introducedIn | 20th century ⓘ |
| nameExpandsTo | closure-finite weak topology complex ⓘ |
| typicalExample |
Eilenberg–MacLane spaces
NERFINISHED
ⓘ
Grassmannians with CW structure ⓘ classifying spaces of groups ⓘ projective spaces with cell structure ⓘ spheres with standard cell decomposition ⓘ |
| usedIn |
cellular homology
ⓘ
cohomology theory ⓘ homology theory ⓘ homotopy groups of spheres ⓘ homotopy theory ⓘ spectral sequences ⓘ stable homotopy theory ⓘ |
How these facts were elicited
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Subject: CW complexes Description of subject: CW complexes are topological spaces built by inductively attaching cells of increasing dimension, providing a flexible and combinatorially tractable framework for algebraic topology.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.