Home On Brauer–Kuroda type relations of S-class numbers in dihedral extensions
Article
Licensed
Unlicensed Requires Authentication

On Brauer–Kuroda type relations of S-class numbers in dihedral extensions

  • Alex Bartel EMAIL logo
Published/Copyright: October 5, 2011

Abstract

Let F/k be a Galois extension of number fields with dihedral Galois group of order 2q, where q is an odd integer. We express a certain quotient of S-class numbers of intermediate fields, arising from Brauer–Kuroda relations, as a unit index. Our formula is valid for arbitrary extensions with Galois group D2q and for arbitrary Galois-stable sets of primes S, containing the Archimedean ones. Our results have curious applications to determining the Galois module structure of the units modulo the roots of unity of a D2q-extension from class numbers and S-class numbers. The techniques we use are mainly representation theoretic and we consider the representation theoretic results we obtain to be of independent interest.

Received: 2010-11-16
Published Online: 2011-10-05
Published in Print: 2012-07

©[2012] by Walter de Gruyter Berlin Boston

Downloaded on 28.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/CRELLE.2011.152/html
Scroll to top button