Kronecker–Weber theorem
E100232
The Kronecker–Weber theorem is a fundamental result in algebraic number theory stating that every finite abelian extension of the rational numbers is contained in a cyclotomic field generated by roots of unity.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Kronecker–Weber theorem canonical | 3 |
| Kronecker–Weber theorem as a special case | 1 |
Statements (43)
| Predicate | Object |
|---|---|
| instanceOf | theorem in algebraic number theory ⓘ |
| appliesTo | finite Galois extensions of Q with abelian Galois group ⓘ |
| characterizes |
finite abelian extensions of Q as subfields of cyclotomic fields
ⓘ
maximal abelian extension of Q ⓘ |
| concerns |
abelian Galois extensions
ⓘ
class field theory over Q ⓘ extensions of the rational number field Q ⓘ |
| describes | finite abelian extensions of the rational numbers ⓘ |
| domain |
Galois extensions of Q
ⓘ
number fields ⓘ |
| equivalentTo | statement that every finite abelian extension of Q has conductor n for some n and is contained in Q(ζ_n) ⓘ |
| excludes | non-abelian extensions of Q ⓘ |
| field | algebraic number theory ⓘ |
| generalizationOf | properties of cyclotomic fields studied by Gauss ⓘ |
| hasConsequence |
classification of finite abelian extensions of Q by conductors
ⓘ
description of abelian Galois groups of Q as quotients of (Z/nZ)^× ⓘ |
| historicalPeriod | 19th century mathematics ⓘ |
| implies |
Q^ab = ⋃_n Q(ζ_n)
ⓘ
the maximal abelian extension of Q is the union of all cyclotomic fields ⓘ |
| involves |
cyclotomic fields
ⓘ
roots of unity ⓘ |
| isPartOf | global class field theory ⓘ |
| namedAfter |
Heinrich Martin Weber
ⓘ
Leopold Kronecker ⓘ |
| originallyFormulatedFor | abelian extensions of Q ⓘ |
| provedBy |
Heinrich Martin Weber
ⓘ
Leopold Kronecker ⓘ |
| relatedTo |
Hilbert’s twelfth problem
ⓘ
surface form:
Artin reciprocity law
Dirichlet characters ⓘ Hilbert class field ⓘ Hilbert’s twelfth problem ⓘ
surface form:
Kronecker Jugendtraum
ray class fields over Q ⓘ |
| standardReference |
Algebraic Number Theory textbooks
ⓘ
Cassels–Fröhlich: Algebraic Number Theory ⓘ Neukirch: Algebraic Number Theory ⓘ |
| states |
every finite abelian extension of Q is contained in Q(ζ_n) for some n
ⓘ
every finite abelian extension of the rational numbers is contained in a cyclotomic field ⓘ |
| usesConcept |
Galois group
ⓘ
abelian group ⓘ conductor of an abelian extension ⓘ cyclotomic polynomial ⓘ local fields at primes of Q ⓘ ramification in number fields ⓘ |
Referenced by (4)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
cyclotomic field
subject surface form:
cyclotomic field
this entity surface form:
Kronecker–Weber theorem as a special case