existence of extensions of field isomorphisms to splitting fields
The following theorem implies the essential uniqueness of splitting fields and algebraic closures
.
Theorem.
Let σ:F→F′ be an isomorphism of fields, S={fα:α∈A} a set of non-constant polynomials
in F[X], and S′={σ(fα):α∈A} the corresponding set of polynomials in F′[X]. If K is a splitting field of S over F and K′ a splitting field of S′ over F′, then σ may be extended to an isomorphism of K and K′.
Corollary.
If F is a field and S a set of non-constant polynomials in F[X], then any two splitting fields of S over F are F-isomorphic. In particular, any two algebraic closures of F are F-isomorphic.
Title | existence of extensions of field isomorphisms to splitting fields |
---|---|
Canonical name | ExistenceOfExtensionsOfFieldIsomorphismsToSplittingFields |
Date of creation | 2013-03-22 18:37:59 |
Last modified on | 2013-03-22 18:37:59 |
Owner | azdbacks4234 (14155) |
Last modified by | azdbacks4234 (14155) |
Numerical id | 4 |
Author | azdbacks4234 (14155) |
Entry type | Theorem |
Classification | msc 12F05 |
Related topic | SplittingField |