Unit indices of some imaginary composite quadratic fields. II

Mikihito Hirabayashi

Vol. 173 (1996), No. 1, 93–104

DOI: 10.2140/pjm.1996.173.93

Abstract

Let K be an imaginary abelian number field of type (2, 2, 2, 2) containing the 8-th cyclotomic field Q(,). Using the fundamental units of real quadratic subfields of K, we give a necessary and sufficient condition for the unit index Q_K of K to be equal to 2.

Mathematical Subject Classification 2000

Primary: 11R27

Secondary: 11R20

Milestones

Received: 17 September 1993

Published: 1 March 1996