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Heuristics for 2-class towers of cyclic cubic fields. (English) Zbl 07815484

Let \(K\) be a cyclic, cubic number field. It is known that the rank \(d\) of the \(2\)-class group \(\text{Cl}_2(K)\) of \(K\) is even and equals the rank of the narrow \(2\)-class group \(\text{Cl}_2^+(K)\). The authors explore the \(2\)-class field tower of \(K\) for the case \(d=2\) by investigating \(G_2(K)\), the Galois group of the maximal unramified \(2\)-extension of \(K\) over \(K\) (and also consider the narrow case). They describe all possible Galois groups up to the fourth layer of the \(2\)-class field tower, give their relative frequencies out of a sample of 500000 fields, and derive some conjectures in the sense of Cohen-Lenstra heuristics. Here it seems that one should focus on the probability of the IPAD of \(G_2(K)\).

MSC:

11R29 Class numbers, class groups, discriminants
11R37 Class field theory
11R16 Cubic and quartic extensions

Software:

PARI/GP; Magma

References:

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