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On some class number relations for Galois extensions

Published online by Cambridge University Press:  22 January 2016

Takashi Ono*
Affiliation:
Department of Mathematics, The Johns Hopkins University, Baltimore, MD 21218, U. S. A.
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Let k be an algebraic number field of finite degree over Q, the field of rationals, and K be an extension of finite degree over k. By the use of the class number of algebraic tori, we can introduce an arithmetical invariant E(K/k) for the extension K/k. When k = Q and K is quadratic over Q, the formula of Gauss on the genera of binary quadratic forms, i.e. the formula where = the class number of K in the narrow sense, the number of classes is a genus of the norm form of K/Q and tK = the number of distinct prime factors of the discriminant of K, may be considered as an equality between E(K/Q) and other arithmetical invariants of K.

Type
Research Article
Copyright
Copyright © Editorial Board of Nagoya Mathematical Journal 1987

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