Abstract
Let \(F\) be a global field. In this work, we show that the Brauer–Manin condition on adelic points for subvarieties of a torus \(T_F\) over \(F\) cuts out exactly the rational points, if either \(F\) is a function field or, if \(F={\mathbb Q}\) and \(T_F\) is split. As an application, we prove a conjecture of Harari–Voloch over global function fields which states, roughly speaking, that on any rational hyperbolic curve, the local integral points with the Brauer–Manin condition are the global integral points. Finally we prove for tori over number fields a theorem of Stoll on adelic points of zero-dimensional subvarieties in abelian varieties.
Similar content being viewed by others
Notes
In this case \(\infty _F=\emptyset \) and \(S\) can be empty, \(P_{\emptyset }\) is then the identity map.
References
Bosch, S., Lütkebohmert, W., Raynaud, M.: Néron Models, Ergebnisse der Mathematics 3, vol. 21. Springer, Berlin, Heidelberg (1990)
Colliot-Thélène, J.-L.: Letter to D. Harari and F. Voloch (2010) (personal communication)
Colliot-Thélène, J.-L., Xu, F.: Brauer-Manin obstruction for integral points of homogeneous spaces and representations by integral quadratic forms. Compos. Math. 145, 309–363 (2009)
Colliot-Thélène, J.-L., Xu, F.: Strong approximation for the total space of certain quadric fibrations. Acta Arithmetica 157, 169–199 (2013)
Conrad, B.: Weil and Grothendieck approaches to adelic points. Enseign. Math. 58, 61–97 (2012)
Conrad, B.: Deligne’s notes on Nagata compactifications. J. Ramanujan Math. Soc. 22, 205–257 (2007)
González-Avilés, C.D., Tan, K.S.: The generalized Cassels–Tate duality exact sequence for 1-motives. Math. Res. Lett. 16, 827–839 (2009)
Grothendieck, A., Dieudonné, J.: Éléments de géométrie algébrique. Publ. Math. IHES 4, 8, 11, 17, 20, 24, 28, 32 (1960–1967)
Grothendieck, A.: Groupe de Brauer I, Dix Exposés sur la Cohomologie des Schémas. North-Holland, Amsterdam (1968)
Harari, D.: Le défaut d’approximation forte pour les groupes algébriques commutatifs. Algebra Number Theory 2, 595–611 (2008)
Harari, D., Szamuely, T.: Arithmetic duality theorems for 1-motives. J. Reine Angew. Math. 578, 93–128 (2005)
Harari, D., Voloch, J.F.: The Brauer-Manin obstruction for integral points on curves. Math. Proc. Cambridge Philos. Soc. 149, 413–421 (2010)
Harder, G.: Minkowskiche Reduktiontheorie über Funktionkörpern. Invent. Math. 7(1), 33–54 (1969)
Lütkebohmert, W.: On compactification of schemes. Manuscr. Math. 80, 95–111 (1993)
Milne, J.S.: Étale Cohomology. Princeton Press, Princeton, New Jersey (1980)
Neukirch, J., Schmidt, A., Wingberg, K.: Cohomology of Number Fields, Grundlehren, vol. 323, 2nd edn. Springer, Berlin, Heidelberg (2008)
Nikolov, N., Segal, D.: On finitely generated profinite groups, I: strong completeness and uniform bounds. Ann. Math. 165, 171–238 (2007)
Poonen, B., Voloch, J.F.: The Brauer–Manin obstruction for subvarieties of abelian varieties over function fields. Ann. Math. 171(1), 511–532 (2010)
Shyr, J.-M.: A generalization of Dirichlet’s unit theorem. J. Number Theory 9, 213–217 (1977)
Skorobogatov, A.: Torsors and Rational Points, Cambridge Tracts in Mathematics, vol. 144. Cambridge University Press, Cambridge (2001)
Skorobogatov, A., Zarhin, Y.: The Brauer group and the Brauer–Manin set of product varieties. J. Eur. Math. Soc. 16, 749–769 (2014)
Stoll, M.: Finite descent obstructions and rational points on curves. Algebra Number Theory 1, 349–391 (2007)
Sun, C.-L.: Product of local points of subvarieties of almost isotrivial semi-abelian varieties over a global function field. Int. Math. Res. Notices 2013, 4477–4498 (2013)
Sun, C.-L.: The Brauer–Manin–Scharaschkin obstruction for subvarieties of a semi-abelian variety and its dynamical analog. J. Number Theory (to appear)
Wei, D., Xu, F.: Integral points for groups of multiplicative type. Adv. Math. 232, 36–56 (2013)
Acknowledgments
We would like to thank J.-L. Colliot-Thélène, D. Harari, Y. Liang and F. Voloch for helpful discussions. We would also like to thank Liang-Chung Hsia for drawing our attention to [23]. We thank the referee for a careful reading of the manuscript and for pointing out some inaccuracies. The first named author thanks Capital Normal University, where part of this work was done, for its support. The second named author is supported by the ALGANT program in Université de Bordeaux, MPI for mathematics at Bonn from September–October 2014 and NSFC Grant No. 11031004.