Czechoslovak Mathematical Journal, Vol. 73, No. 3, pp. 937-940, 2023


On the class number of the maximal real subfields of a family of cyclotomic fields

Mahesh Kumar Ram

Received August 24, 2022.   Published online April 27, 2023.

Abstract:  For any square-free positive integer $m\equiv{10}\pmod{16}$ with $m\geq26$, we prove that the class number of the real cyclotomic field $\mathbb{Q}(\zeta_{4m}+\zeta_{4m}^{-1})$ is greater than $1$, where $\zeta_{4m}$ is a primitive $4m$th root of unity.
Keywords:  maximal real subfield of cyclotomic field; real quadratic field; class number
Classification MSC:  11R29, 11R18, 11R11


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Affiliations:   Mahesh Kumar Ram, Indian Institute of Science Education and Research, Govt. ITI Building Engg. School Junction, Brahmapur, Odisha 760010, India, e-mail: maheshk@iiserbpr.ac.in


 
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