Hopf--Galois structures of cyclic type on parallel extensions of prime power degree
Group Theory
2026-05-08 v2 Number Theory
Rings and Algebras
Abstract
Let be any finite separable extension with normal closure . An extension is said to be \textit{parallel to L/K} if is an intermediate field of with . We study the following question -- Given that admits a Hopf--Galois structure of type , does it imply that every extension parallel to also admits a Hopf--Galois structure of type ? We completely solve this problem when the degree is a prime power and the type is cyclic. Our approach is group-theoretic and uses the work of Greither--Pareigis and Byott.
Keywords
Cite
@article{arxiv.2510.14473,
title = {Hopf--Galois structures of cyclic type on parallel extensions of prime power degree},
author = {Andrew Darlington and Cindy Tsang},
journal= {arXiv preprint arXiv:2510.14473},
year = {2026}
}
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32 pages