Article
Keywords:
maximal real subfield of cyclotomic field; real quadratic field; class number
Summary:
For any square-free positive integer $m\equiv {10}\pmod {16}$ with $m\geq 26$, 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.
References:
[3] Hasse, H.:
Über mehrklassige, aber eingeschlechtige reell-quadratische Zahlkörper. Elem. Math. 20 (1965), 49-59 German.
MR 191889 |
Zbl 0128.03502