Abstract
A necessary and sufficient condition is given for the ideal class group H(m) of a real quadratic field Q (√m) to contain a cyclic subgroup of ordern. Some criteria satisfying the condition are also obtained. And eight types of such fields are proved to have this property, e.g. fields withm=(z n+t−1)2+4t(witht|z n−1), which contains the well-known fields withm=4z n+1 andm=4z 2n+4 as special cases.
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Project supported by the National Natural Science Foundation of China.
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Washington, L.C., Zhang, X. Ideal class groups and their subgroups of real quadratic fields. Sci. China Ser. A-Math. 40, 909–916 (1997). https://doi.org/10.1007/BF02878670
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DOI: https://doi.org/10.1007/BF02878670