Abstract
We determine the 3-class groups of \({\mathbb {Q}}(\root 3 \of {p})\) and \(K={\mathbb {Q}}(\root 3 \of {p},\sqrt{-3})\) when \(p\equiv 4,7\bmod 9\) is a prime and 3 is a cube modulo p. This confirms a conjecture made by Barrucand-Cohn, and proves the last remaining case of a conjecture of Lemmermeyer on the 3-class group of K.
Similar content being viewed by others
References
Aouissi, S., Talbi, M., Ismaili, M.C., Azizi, A.: On a conjecture of Lemmermeyer. Int. J. Number Theory 16(7), 1407–1424 (2020)
Barrucand, P., Cohn, H.: A rational genus, class number divisibility, and unit theory for pure cubic fields. J. Number Theory 2, 7–21 (1970)
Barrucand, P., Cohn, H.: Remarks on principal factors in a relative cubic field. J. Number Theory 3, 226–239 (1971)
Barrucand, P., Williams, H.C., Baniuk, L.: A computational technique for determining the class number of a pure cubic field. Math. Comput. 30(134), 312–323 (1976)
Calegari, F., Emerton, M.: On the ramification of Hecke algebras at Eisenstein primes. Invent. Math. 160(1), 97–144 (2005)
Gerth, F.E., III.: On 3-class groups of certain pure cubic fields. Bull. Austral. Math. Soc. 72(3), 471–476 (2005)
Honda, T.: Pure cubic fields whose class numbers are multiples of three. J. Number Theory 3, 7–12 (1971)
Lemmermeyer, F.: Class field towers (2010). http://www.rzuser.uni-heidelberg.de/~hb3/publ/pcft.pdf
Li, J., Ouyang, Y., Xu, Y., Zhang, S.: \(\ell \)-class groups of fields in Kummer towers. Publ. Mat. (2020), to appear. arXiv:1905.04966
Li, J., Yu, C.F.: The Chevalley–Gras formula over global fields. J. Théor. Nombres Bordeaux 32(2), 525–543 (2020)
Washington, L.C.: Introduction to Cyclotomic Fields. Graduate Texts in Mathematics, vol. 83. Springer, New York (1982)
Williams, H..C.: Determination of principal factors in \({\cal{Q}}(\sqrt{D})\) and \({\cal{Q}}(\root 3 \of {D})\). Math. Comput. 38(157), 261–274 (1982)
Acknowledgements
The authors would like to thank Franz Lemmermeyer, René Schoof and Yi Ouyang for helpful comments on this article. The authors are partially supported by Anhui Initiative in Quantum Information Technologies (Grant no. AHY150200) and by the Fundamental Research Funds for the Central Universities (Grant No. WK3470000020 and Grant no. WK0010000061 respectively). The second named author is also supported by NSFC (Grant no. 12001510).
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Li, J., Zhang, S. The 3-class groups of \(\mathbb {Q}(\root 3 \of {p})\) and its normal closure. Math. Z. 300, 209–215 (2022). https://doi.org/10.1007/s00209-021-02797-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00209-021-02797-5