Whitney approximation theorem
E53941
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.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Whitney approximation theorem canonical | 5 |
| strong Whitney approximation theorem | 1 |
| weak Whitney approximation theorem | 1 |
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
mathematical theorem
ⓘ
theorem in differential topology ⓘ |
| appearsIn |
textbooks on differential topology
ⓘ
textbooks on smooth manifolds ⓘ |
| asserts |
continuous functions can be approximated arbitrarily well by smooth functions in the compact-open topology
ⓘ
every continuous map between smooth manifolds can be uniformly approximated by smooth maps ⓘ for manifolds without boundary, continuous maps can be approximated by smooth maps that are homotopic to the original map ⓘ |
| assumes |
paracompactness of manifolds in standard formulations
ⓘ
smooth structure on manifolds ⓘ |
| classification |
Weierstrass approximation theorem
ⓘ
surface form:
approximation theorem
|
| codomainCondition | target is a smooth manifold ⓘ |
| concerns |
approximation of continuous maps by smooth maps
ⓘ
continuous functions between smooth manifolds ⓘ smooth manifolds ⓘ |
| domainCondition | source is a smooth manifold ⓘ |
| field |
differential geometry
ⓘ
differential topology ⓘ topology ⓘ |
| generalizes | approximation of continuous functions on subsets of Euclidean space by smooth functions ⓘ |
| hasVersion |
Whitney approximation theorem
self-linksurface differs
ⓘ
surface form:
strong Whitney approximation theorem
Whitney approximation theorem self-linksurface differs ⓘ
surface form:
weak Whitney approximation theorem
|
| historicalPeriod | 20th century mathematics ⓘ |
| holdsFor | maps between manifolds with boundary under suitable compatibility conditions ⓘ |
| implies |
C^∞(M,N) is dense in C^0(M,N) for smooth manifolds M and N under suitable topologies
ⓘ
smooth maps are dense in the space of continuous maps between smooth manifolds ⓘ |
| mathematicsSubjectClassification |
57Rxx
ⓘ
58Cxx ⓘ |
| namedAfter | Hassler Whitney ⓘ |
| namedEntityType | result in mathematics ⓘ |
| relatedTo |
Weierstrass approximation theorem
ⓘ
surface form:
Stone–Weierstrass theorem
Weierstrass approximation theorem ⓘ Whitney embedding theorem ⓘ |
| standardReference |
J. Lee, Introduction to Smooth Manifolds
ⓘ
J. Munkres, Elementary Differential Topology ⓘ M. Hirsch, Differential Topology ⓘ |
| strongVersionConcerns | approximation relative to a closed subset ⓘ |
| strongVersionStates | a continuous map can be approximated by a smooth map that agrees with it on a closed subset where it is already smooth ⓘ |
| topologyUsed |
C^0 topology on spaces of maps
ⓘ
compact-open topology ⓘ |
| typicalProofUses |
local coordinate charts
ⓘ
partitions of unity ⓘ smoothing by convolution in Euclidean space ⓘ |
| usedIn |
approximation of sections of fiber bundles
ⓘ
construction of smooth structures ⓘ differential topology proofs involving transversality ⓘ homotopy theory of manifolds ⓘ smoothing of continuous maps ⓘ |
| weakVersionStates | every continuous map between smooth manifolds can be uniformly approximated by smooth maps ⓘ |
Referenced by (7)
Full triples — surface form annotated when it differs from this entity's canonical label.
Whitney approximation theorem
→
hasVersion
→
Whitney approximation theorem
self-linksurface differs
ⓘ
this entity surface form:
weak Whitney approximation theorem
Whitney approximation theorem
→
hasVersion
→
Whitney approximation theorem
self-linksurface differs
ⓘ
this entity surface form:
strong Whitney approximation theorem
subject surface form:
Hassler Whitney
subject surface form:
Differential Topology (book)