Noether field

E171227

A Noether field is a type of field extension studied in invariant theory and Galois theory, arising as the fixed field of a group action on a rational function field and central to questions about rationality in Noether’s problem.

All labels observed (1)

Label Occurrences
Noether field canonical 1

How this entity was disambiguated

Statements (42)

Predicate Object
instanceOf field extension
fixed field
mathematical object
appearsIn Noether’s original formulation of the inverse Galois problem
arisesAs fixed field of a group action on a rational function field
associatedWith finite group actions
linear representations of groups
canBeViewedAs function field of a quotient variety V/G
centralTo questions about rationality in Noether’s problem
definedAs fixed field K(x_1,…,x_n)^G of a group G acting on a rational function field K(x_1,…,x_n)
dependsOn choice of base field K
group G
representation of G on the variables x_1,…,x_n
generalizationOf fixed field of permutation action on variables
hasBaseField K
hasConstruction take rational function field K(x_1,…,x_n) and then take invariants under a group action of G
hasDomain algebra
algebraic geometry
field theory
hasElementForm rational functions in x_1,…,x_n invariant under G
hasHistoricalContext introduced in the study of Noether’s problem on rationality of invariant fields
hasOpenProblem classification of groups G for which K(x_1,…,x_n)^G is rational over K
hasProperty may or may not be purely transcendental over the base field
isFixedFieldOf group action of G on K(x_1,…,x_n)
isInvariantUnder action of G
isSubfieldOf rational function field K(x_1,…,x_n)
namedAfter Emmy Noether
questionAsksWhether K(x_1,…,x_n)^G is purely transcendental over K
relatedTo Noether's problem
surface form: Noether’s problem

function field of a variety
rational function field
relatedToConcept generic Galois extension
rationality problem
stable rationality
unirationality
studiedIn Galois theory
invariant theory
usedIn construction of generic polynomials
realization of finite groups as Galois groups over fields
usedToStudy Galois groups
invariant subfields
rationality of quotient varieties

How these facts were elicited

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.

Noether's problem relatedConcept Noether field