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Abundant central extensions of non-trivial genera

Published online by Cambridge University Press:  22 January 2016

K. Miyake
Affiliation:
Department of Mathematics, College of General Education, Nagoya University, Nagoya 464, Japan
N. Ormerod
Affiliation:
School of Mathematics, The University of New South Wales, PO Box 1, Kensington N.S.W. 2033, Australia
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Let k be either a local or a global field, and K be a finite Galois extension of k with g = Gal (K/k). Let L be a Galois extension of K which is also Galois over k. Such an extension is called central if Gal(L/iT) lies inside the centre of Gal(L/K). Clearly L is abelian over K. Next set L* = L∩K · kab where kab is the maximal abelian extension of k in its algebraic closure. This is the genus field of L over K/k.

Type
Research Article
Copyright
Copyright © Editorial Board of Nagoya Mathematical Journal 1984

References

[ 1 ] Fröhlich, A., On fields of class two, Proc. London Math. Soc. (3), 4 (1954), 235256.Google Scholar
[ 2 ] Fröhlich, A., (ed.), Algebraic Number Fields, Acad. Press, London: New York: San Francisco, 1977.Google Scholar
[ 3 ] Hochschild, G. and Serre, J.-P., Cohomology of group extensions, Trans. Amer. Math. Soc, 74 (1953), 110134.Google Scholar
[ 4 ] Miyake, K., Central extensions and Schur’s multiplicators of Galois groups, Nagoya Math. J., 90 (1983), 137144.CrossRefGoogle Scholar
[ 5 ] Miyake, K., On central extensions of a Galois extension of algebraic number fields, Nagoya Math. J., 93 (1984), 133148.CrossRefGoogle Scholar
[ 6 ] Serre, J.-P., Modular forms of weight one and Galois representations, in Fröhlich [2], 193268.Google Scholar