On a variant of the Beckmann--Black problem
Number Theory
2021-11-16 v1
Abstract
Given a field and a finite group , the Beckmann--Black problem asks whether every Galois field extension with group is the specialization at some of some Galois field extension with group and . We show that the answer is positive for arbitrary and , if one waives the requirement that is normal. In fact, our result holds if is any given subgroup of and, in the special case , we provide a similar conclusion even if is not normal. We next derive that, given a division ring and an automorphism of of finite order, all finite groups occur as automorphism groups over the skew field of fractions of the twisted polynomial ring .
Keywords
Cite
@article{arxiv.2111.07155,
title = {On a variant of the Beckmann--Black problem},
author = {François Legrand},
journal= {arXiv preprint arXiv:2111.07155},
year = {2021}
}