Pontryagin duality
E681628
Pontryagin duality is a fundamental theorem in harmonic analysis and topological group theory that establishes a duality between locally compact abelian groups and their groups of continuous characters.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| Pontryagin duality for locally compact abelian groups | 1 |
Statements (50)
| Predicate | Object |
|---|---|
| instanceOf |
mathematical duality theory
ⓘ
theorem in harmonic analysis ⓘ theorem in topological group theory ⓘ |
| appliesTo | locally compact abelian groups ⓘ |
| assertsIsomorphism | canonical evaluation map from a group to its double dual is an isomorphism ⓘ |
| codomainCategory | opposite category of locally compact abelian groups ⓘ |
| coreStatement |
every locally compact abelian group is canonically isomorphic to its double dual
ⓘ
the dual of a locally compact abelian group is a locally compact abelian group ⓘ the duality functor on locally compact abelian groups is an involutive contravariant equivalence of categories ⓘ |
| developedBy | Lev Pontryagin NERFINISHED ⓘ |
| domainCategory | category of locally compact abelian groups ⓘ |
| failsFor | non-abelian locally compact groups in its classical form ⓘ |
| field |
abstract harmonic analysis
ⓘ
harmonic analysis ⓘ topological group theory ⓘ |
| formalizesAs | contravariant equivalence between a category and its opposite ⓘ |
| hasExample |
dual of a finite abelian group is isomorphic to the group itself
ⓘ
dual of a real vector space regarded as an additive group is isomorphic to its algebraic dual with appropriate topology ⓘ dual of the circle group is the integers ⓘ dual of the integers is the circle group ⓘ |
| historicalPeriod | 20th century mathematics ⓘ |
| inspired | non-abelian duality theories ⓘ |
| involvesConstruction |
character group
ⓘ
group of continuous homomorphisms into the circle group ⓘ |
| mathematicalArea |
abstract algebra
ⓘ
category theory ⓘ topology ⓘ |
| namedAfter | Lev Pontryagin NERFINISHED ⓘ |
| relatedConcept |
character group functor
ⓘ
reflexive group ⓘ |
| relatedResult |
Gelfand duality
NERFINISHED
ⓘ
Stone duality ⓘ |
| relatesConcept |
Fourier analysis on groups
NERFINISHED
ⓘ
Fourier transform NERFINISHED ⓘ continuous characters ⓘ dual group ⓘ group characters ⓘ topological groups ⓘ |
| requiresCondition |
abelian group structure
ⓘ
local compactness ⓘ |
| specialCaseOf |
duality between objects and characters
ⓘ
duality theory in functional analysis ⓘ |
| usedIn |
Fourier series
NERFINISHED
ⓘ
Fourier transform on locally compact abelian groups ⓘ Tate's thesis NERFINISHED ⓘ harmonic analysis on adelic groups ⓘ number theory ⓘ representation theory of abelian groups ⓘ |
| usesTargetGroup |
circle group
ⓘ
unit complex numbers ⓘ |
Referenced by (5)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Pontryagin duality for locally compact abelian groups