Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-24T12:34:44.138Z Has data issue: false hasContentIssue false

The 2-Rank of the Class Group of Imaginary Bicyclic Biquadratic Fields

Published online by Cambridge University Press:  20 November 2018

Thomas M. McCall
Affiliation:
Department of Mathematics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, 24061-0123
Charles J. Parry
Affiliation:
Department of Mathematics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, 24061-0123
Ramona R. Ranalli
Affiliation:
Department of Mathematics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, 24061-0123
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A formula is obtained for the rank of the 2-Sylow subgroup of the ideal class group of imaginary bicyclic biquadratic fields. This formula involves the number of primes that ramify in the field, the ranks of the 2-Sylow subgroups of the ideal class groups of the quadratic subfields and the rank of a Z2-matrix determined by Legendre symbols involving pairs of ramified primes. As applications, all subfields with both 2- class and class group Z2×Z2 are determined. The final results assume the completeness of D. A. Buell’s list of imaginary fields with small class numbers.

Keywords

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1997

References

1. Arno, S., The imaginary quadratic fields of class number 4, Acta Arithmetica LX(1992), 321334.Google Scholar
2. Brown, E., Class numbers of complex quadratic fields, J. Number Theory 6(1974), 185191.Google Scholar
3. Brown, E., Class numbers of real quadratic number fields, Trans.Amer.Math. Soc. 190(1974), 99107.Google Scholar
4. Brown, E., The power of 2 dividing the class-number of a binary quadratic discriminant, J. Number Theory 5(1973), 413419.Google Scholar
5. Brown, E. and Parry, C.J., Class numbers of imaginary quadratic fields having exactly three discriminantal divisors, J.Reine Angew. Math. 260(1973), 3134.Google Scholar
6. Buell, D.A., Small class numbers and extreme values of L-functions of quadratic fields, Math. Comp. 31(1977), 786796.Google Scholar
7. Kubota, T., Über den bizyklischen biquadratischen Zahlkörper, Nagoya Math. J. 10(1956), 6585.Google Scholar
8. McCall, T.M., Parry, C.J. and Ranalli, R.R., Imaginary bicyclic biquadratic fields with cyclic 2-class group, J. Number Theory 51(1995), 8899.Google Scholar
9. Oriat, B., Groupes des classes d’ideaux des corpos quadratiques, Université de Besancon.Google Scholar
10. Rédei, L. und Reichardt, H., Die Anzahl der durch 4 teilbaren Invarianten der Klassengruppe eines beliebigen quadratischen Zahlkörpers, J. reine angew. Math. 170(1933), 6974.Google Scholar
11. Rédei, L., Arithmetischer Beweis des Satzes über die Anzahl der durch vier teilbaren Invarianten der absoluten Klassengruppe im quadratischen Zahlkörper, J. reine angew. Math. 171(1934), 5560.Google Scholar
12. Rédei, L. und Reichardt, H., Die 2-Ringklassengruppe des quadratischen Zahlkörpers und die Theorie der Pellschen Gleichung, Acta Math. Acad. Sci. Huang. 4(1953), 3187.Google Scholar
13. Stark, H.M., A complete determination of the complex quadratic fields of class number one, Michigan Math. J. 14(1967), 127.Google Scholar
14. Stark, H.M., On complex quadratic fields with class number two, Math. Comp. 29(1975), 289302.Google Scholar