Brouwer fixed-point theorem
E22815
The Brouwer fixed-point theorem is a fundamental result in topology stating that any continuous function from a compact convex set (such as a closed disk) to itself has at least one fixed point.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| Schauder fixed-point theorem | 1 |
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
fixed-point theorem
ⓘ
topological theorem ⓘ |
| appliesTo |
closed disks
ⓘ
closed intervals ⓘ closed n-dimensional balls ⓘ compact convex subsets of Euclidean space ⓘ continuous functions ⓘ |
| assumes |
compactness of the domain
ⓘ
continuity of the map ⓘ convexity of the domain ⓘ |
| category | existence theorem ⓘ |
| conclusion | existence of a fixed point ⓘ |
| dimension |
does not generally extend to infinite-dimensional spaces
ⓘ
holds in all finite dimensions ⓘ |
| domainCondition |
compact set
ⓘ
convex set ⓘ subset of Euclidean space ⓘ |
| equivalentTo | Sperner's lemma under suitable conditions ⓘ |
| failsIf |
domain is not compact
ⓘ
domain is not convex ⓘ map is not continuous ⓘ |
| field |
economics
ⓘ
functional analysis ⓘ game theory ⓘ nonlinear analysis ⓘ topology ⓘ |
| hasCombinatorialVersion | Sperner's lemma ⓘ |
| implies | Borsuk–Ulam theorem in certain formulations ⓘ |
| importance | fundamental result in topology ⓘ |
| mapCondition | continuous self-map ⓘ |
| namedAfter | Luitzen Egbertus Jan Brouwer ⓘ |
| nonConstructive | true ⓘ |
| proofMethod |
combinatorial arguments
ⓘ
degree theory ⓘ homology theory ⓘ topological methods ⓘ |
| proposedBy |
Luitzen Egbertus Jan Brouwer
ⓘ
surface form:
L. E. J. Brouwer
|
| relatedTo |
Banach fixed-point theorem
ⓘ
Kakutani fixed-point theorem ⓘ Schauder fixed-point theorem ⓘ |
| statement |
Every continuous function from a closed n-dimensional ball to itself has at least one fixed point.
ⓘ
Every continuous function from a compact convex subset of R^n to itself has at least one fixed point. ⓘ |
| usedIn |
combinatorial topology
ⓘ
differential equations ⓘ general equilibrium theory in economics ⓘ nonlinear boundary value problems ⓘ proof of Nash equilibrium existence ⓘ topological degree theory ⓘ |
| yearProved | 1911 ⓘ |
Referenced by (4)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Schauder fixed-point theorem