Abstract.
Cohen and Odoni prove that every CM–field can be generated by an eigenvalue of some skew–symmetric matrix with rational coefficients. It is natural to ask for the minimal dimension of such a matrix. They show that every CM–field of degree 2n is generated by an eigenvalue of a skew–symmetric matrix over Q of dimension at most 4n+2. The aim of the present paper is to improve this bound.
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Bayer-Fluckiger, E., Berhuy, G. & Chuard–Koulmann, P. CM–fields and skew–symmetric matrices. manuscripta math. 114, 351–359 (2004). https://doi.org/10.1007/s00229-004-0462-0
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DOI: https://doi.org/10.1007/s00229-004-0462-0