Abstract
In this note, we are interested in local-global principles for multinorm equations \(\prod\nolimits_{i = 1}^n {{N_{{L_i}/k}}({z_i}} ) = a\) where k is a global field, L i /k are finite separable field extensions and a ∈ k*.
In particular, we prove a result relating the Hasse principle and weak approximation for this equation to the Hasse principle and weak approximation for some classical norm equation N F/k (w) = a where \(F: = \bigcap\nolimits_{i = 1}^n {{L_i}} \). It provides a proof of a “weak approximation” analogue of a recent conjecture by Pollio and Rapinchuk about the multinorm principle. We also provide a counterexample to the original conjecture concerning the Hasse principle.
Similar content being viewed by others
References
J.-L. Colliot-Thélène, L’arithmétique des variétés rationnelles, Annales de la Faculté des Sciences de Toulouse. Mathématiques 3 (1992), 295–336.
J.-L. Colliot-Thélène, Groupe de Brauer non ramifié d’espaces homogènes de tores, Journal de Théorie des Nombres de Bordeaux, to appear. arXiv:1210.3644.
W. Hürlimann, On algebraic tori of norm type, Commentarii Mathematici Helvetici 59 (1984), 539–549.
G. Karpilovsky, The Schur Multiplier, London Mathematical Society Monographs, Vol. 2, Oxford University Press, New York, 1987.
B. È. Kunyavskiĭ, Arithmetic properties of three-dimensional algebraic tori. Integral lattices and finite linear groups, Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta imeni V. A. Steklova Akademii Nauk SSSR (LOMI) 116 (1982), 102–107, 163.
J. Neukirch, A. Schmidt and K. Wingberg, Cohomology of Number Fields, second edition, Grundlehren der Mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences], Vol. 323, Springer-Verlag, Berlin, 2008.
V. Platonov and A. S. Rapinchuk, Algebraic groups and number theory, Pure and Applied Mathematics, Vol. 139, Academic Press, Boston, MA, 1994.
T. Pollio and A. S. Rapinchuk, The multinorm principle for linearly disjoint Galois extensions, Journal of Number Theory 133 (2013), 802–821.
G. Prasad and A. S. Rapinchuk, Local-global principles for embedding of fields with involution into simple algebras with involution, Commentarii Mathematici Helvetici 85 (2010) 583–645.
J.-J. Sansuc, Groupe de Brauer et arithmétique des groupes algébriques linéaires sur un corps de nombres, Journal für die Reine und Angewandte Mathematik 327 (1981), 12–80.
V. E. Voskresenskiĭ, Algebraicheskie Tory, Izdat Nauka, Moscow, 1977. (Russian)
D. Wei, On the equation N K/k(Ξ) = P(t), preprint (2012), arXiv:1202.4115v2.
D. Wei, The unramified Brauer group of norm one tori, preprint (2012), arXiv:1202.4714v2.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Demarche, C., Wei, D. Hasse principle and weak approximation for multinorm equations. Isr. J. Math. 202, 275–293 (2014). https://doi.org/10.1007/s11856-014-1071-6
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11856-014-1071-6