Abstract
AbstractWe give conditions for Kaplansky fields to admit infinite towers of Galois defect extensions of prime degree. As proofs of the presented facts are constructive, this provides examples of constructions of infinite towers of Galois defect extensions of prime degree. We also give a constructive proof of the fact that a henselian Kaplansky field cannot be defectless-by-finite.
Highlights
IntroductionWe denote by (K, v) a field K equipped with a valuation v
In this paper, we denote by (K, v) a field K equipped with a valuation v
We show that if a Kaplansky field of positive characteristic p admits a Galois defect extension it admits an infinite tower of such extensions
Summary
We denote by (K, v) a field K equipped with a valuation v. See Theorem 1 of [16], which shows the equivalence of conditions (K1) - (K3) with the original “hypothesis A” assumed by Kaplansky He gave an example of a valued field admitting nonisomorphic maximal immediate extensions (cf [6, Section 5]). In the present paper we give conditions for Kaplansky fields to admit infinite towers of Galois defect extensions of prime degree. We show that if a Kaplansky field of positive characteristic p admits a Galois defect extension it admits an infinite tower of such extensions (cf Theorem 3.2). We give conditions for a valued field of characteristic 0 and residue characteristic 2 to admit a infinite tower of defect extensions of degree 2 (cf Theorem 3.6, Corollary 3.7 and Corollary 3.8). The facts mentioned above allow us to give a constructive alternative proof of the fact that Kaplansky fields cannot be defectless-by-finite (cf. Corollary 3.10)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.