International Journal of Mathematics and Mathematical Sciences
Volume 2007 (2007), Article ID 89713, 8 pages
Research Article

On the Common Index Divisors of a Dihedral Field of Prime Degree

Blair K. Spearman,1 Kenneth S. Williams,2 and Qiduan Yang1

1Department of Mathematics and Statistics, University of British Columbia Okanagan, Kelowna V1V 1V7, BC, Canada
2School of Mathematics and Statistics, Carleton University, Ottawa K1S 5B6, ON, Canada

Received 11 September 2006; Revised 6 January 2007; Accepted 6 January 2007

Academic Editor: Dihua Jiang

Copyright © 2007 Blair K. Spearman et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A criterion for a prime to be a common index divisor of a dihedral field of prime degree is given. This criterion is used to determine the index of families of dihedral fields of degrees 5 and 7.