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Explicit non-Gorenstein \(R=\mathbb{T}\) via rank bounds. II: Computational aspects. (English) Zbl 1540.11057

Summary: This is the second in a pair of papers about residually reducible Galois deformation rings with non-optimal level. In the first paper, we proved a Galois-theoretic criterion for the deformation ring to be as small as possible. This paper focuses on the computations needed to verify this criterion. We adapt a technique developed by Sharifi to compute number fields with twisted-Heisenberg Galois group and prescribed ramification, and compute the splitting behavior of primes in these extensions.
For Part I see [The authors, “Explicit non-Gorenstein \(R=\mathbb{T}\) via rank bounds I: Deformation theory’, Preprint, arXiv:2209.00536].

MSC:

11F80 Galois representations
11Y40 Algebraic number theory computations

Software:

CoCalc; SageMath; PARI/GP

References:

[1] Calegari, F.; Emerton, M., On the ramification of Hecke algebras at Eisenstein primes, Invent. Math., 160, 1, 97-144 (2005) · Zbl 1145.11314 · doi:10.1007/s00222-004-0406-z
[2] Fontaine, J-M, Il n’y a pas de variété abélienne sur Z, Invent. Math., 81, 3, 515-538 (1985) · Zbl 0612.14043 · doi:10.1007/BF01388584
[3] Hsu, C., Wake, P., Wang-Erickson, C.: Explicit non-Gorenstein \(R={\mathbb{T}}\) via rank bounds I: Deformation theory (2022). Preprint, arXiv: 2209.00536 [math.NT]
[4] Kraines, D., Massey higher products, Trans. Am. Math. Soc., 124, 431-449 (1966) · Zbl 0146.19201 · doi:10.1090/S0002-9947-1966-0202136-1
[5] Lecouturier, E.: On the Galois structure of the class group of certain Kummer extensions. J. Lond. Math. Soc. (2) 98(1), 35-58 (2018) · Zbl 1457.11154
[6] Lemmermeyer, F., Reciprocity laws (2000), Berlin: Springer Monographs in Mathematics. From Euler to Eisenstein. Springer, Berlin · Zbl 0949.11002 · doi:10.1007/978-3-662-12893-0
[7] Lam, Y.H.J., Liu, Y., Sharifi, R., Wake, P., Wang, J.: Generalized Bockstein maps and Massey products (2021). arXiv:2004.11510v2 [math.NT] · Zbl 1537.20128
[8] May, JP, Matric Massey products, J. Algebra, 12, 533-568 (1969) · Zbl 0192.34302 · doi:10.1016/0021-8693(69)90027-1
[9] Merel, L., L’accouplement de Weil entre le sous-groupe de Shimura et le sous-groupe cuspidal de \(J_0(p)\), J. Reine Angew. Math., 477, 71-115 (1996) · Zbl 0859.11036
[10] Neukirch, J.: Algebraic Number Theory, volume 322 of Grundlehren der mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences]. Springer, Berlin: Translated from the 1992 German original and with a note by Norbert Schappacher. With a foreword by G, Harder (1999)
[11] Stein, W.A., et al.: SageMath, the Sage Mathematics Software System (accessed online through CoCalc). The Sage Development Team (2018). http://www.sagemath.org, https://cocalc.com
[12] Serre, J.-P.: Local Fields, vol. 67 of Graduate Texts in Mathematics. Springer, New York. Translated from the French by Marvin Jay Greenberg (1979) · Zbl 0423.12016
[13] Serre, J-P, Sur les représentations modulaires de degré \(2\) de \({\rm Gal}(\overline{\textbf{ Q} }/{\textbf{ Q} })\), Duke Math. J., 54, 1, 179-230 (1987) · Zbl 0641.10026 · doi:10.1215/S0012-7094-87-05413-5
[14] Sharifi, R.T.: Twisted Heisenberg representations and local conductors. ProQuest LLC, Ann Arbor, MI. Thesis (Ph.D.), The University of Chicago (1999)
[15] Sharifi, RT, Massey products and ideal class groups, J. Reine Angew. Math., 603, 1-33 (2007) · Zbl 1163.11077 · doi:10.1515/CRELLE.2007.010
[16] Tahara, K., On the second cohomology groups of semidirect products, Math. Z., 129, 365-379 (1972) · Zbl 0238.20068 · doi:10.1007/BF01181625
[17] The PARI Group, Univ. Bordeaux. PARI/GP version 2.13.4 (2022). http://pari.math.u-bordeaux.fr/
[18] Wake, P., The Eisenstein ideal for weight \(k\) and a Bloch-Kato conjecture for tame families, J. Eur. Math. Soc. (2022) · Zbl 1532.11058 · doi:10.4171/JEMS/1251
[19] Wake, P.; Wang-Erickson, C., The rank of Mazur’s Eisenstein ideal, Duke Math. J., 169, 1, 31-115 (2020) · Zbl 1445.11045 · doi:10.1215/00127094-2019-0039
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