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Homogeneous orbit closures and applications

Published online by Cambridge University Press:  28 April 2011

ELON LINDENSTRAUSS
Affiliation:
Einstein Institute of Mathematics, Edmond J. Safra Campus, Givat Ram, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel (email: [email protected])
URI SHAPIRA
Affiliation:
ETH Zürich, Departement Mathematik, Rämistrasse 101, 8092 Zürich, Switzerland (email: [email protected])

Abstract

We give new classes of examples of orbits of the diagonal group in the space of unit volume lattices in ℝd for d≥3 with nice (homogeneous) orbit closures, as well as examples of orbits with explicitly computable but irregular orbit closures. We give Diophantine applications to the former; for instance, we show that, for all γ,δ∈ℝ, where 〈c〉 denotes the distance of a real number c to the integers.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2011

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References

[CSD55]Cassels, J. W. S. and Swinnerton-Dyer, H. P. F.. On the product of three homogeneous linear forms and the indefinite ternary quadratic forms. Philos. Trans. R. Soc. Lond. Ser. A 248 (1955), 7396; MR 0070653(17,14f).Google Scholar
[Dav51]Davenport, H.. Indefinite binary quadratic forms, and Euclid’s algorithm in real quadratic fields. Proc. Lond. Math. Soc. (2) 53 (1951), 6582; MR 0041883(13,15f).Google Scholar
[EKL06]Einsiedler, M., Katok, A. and Lindenstrauss, E.. Invariant measures and the set of exceptions to Littlewood’s conjecture. Ann. of Math. (2) 164(2) (2006), 513560; MR 2247967(2007j:22032).Google Scholar
[EL10]Einsiedler, M. and Lindenstrauss, E.. Diagonal actions on locally homogeneous spaces. Homogeneous Flows, Moduli Spaces and Arithmetic (Clay Mathematics Proceedings, 10). American Mathematical Society, Providence, RI, 2010, pp. 155241.Google Scholar
[EMS97]Eskin, A., Mozes, S. and Shah, N.. Non-divergence of translates of certain algebraic measures. Geom. Funct. Anal. 7(1) (1997), 4880; MR 1437473(98d:22006).Google Scholar
[LW01]Lindenstrauss, E. and Weiss, B.. On sets invariant under the action of the diagonal group. Ergod. Th. & Dynam. Sys. 21(5) (2001), 14811500; MR 1855843(2002j:22009).Google Scholar
[Mar89]Margulis, G. A.. Discrete subgroups and ergodic theory. Number Theory Trace Formulas and Discrete Groups (Oslo, 1987). Academic Press, Boston, MA, 1989, pp. 377398; MR 993328(90k:22013a).Google Scholar
[Mar97]Margulis, G. A.. Oppenheim conjecture. Fields Medallists’ Lectures (World Scientific Series, 20th Century Mathematics, 5). World Scientific Publishers, River Edge, NJ, 1997, pp. 272327; MR 1622909(99e:11046).Google Scholar
[Mar00]Margulis, G. A.. Problems and conjectures in rigidity theory. Mathematics: Frontiers and Perspectives. American Mathematical Society, Providence, RI, 2000, pp. 161174; MR 1754775(2001d:22008).Google Scholar
[Mau]Maucourant, F.. A non-homogeneous orbit closure of a diagonal subgroup. Ann. of Math. (2) 171(1) (2010), 557570.Google Scholar
[MT96]Margulis, G. A. and Tomanov, G. M.. Measure rigidity for almost linear groups and its applications. J. Anal. Math. 69 (1996), 2554; MR 1428093(98i:22016).Google Scholar
[PR72]Prasad, G. and Raghunathan, M. S.. Cartan subgroups and lattices in semi-simple groups. Ann. of Math. (2) 96 (1972), 296317; MR 0302822(46#1965).Google Scholar
[Rat91a]Ratner, M.. On Raghunathan’s measure conjecture. Ann. of Math. (2) 134(3) (1991), 545607; MR 1135878(93a:22009).Google Scholar
[Rat91b]Ratner, M.. Raghunathan’s topological conjecture and distributions of unipotent flows. Duke Math. J. 63(1) (1991), 235280; MR 1106945(93f:22012).Google Scholar
[Sha]Shapira, U.. A solution to a problem of Cassels and Diophantine properties of cubic numbers. Ann of Math. (2) 173(1) (2011), 543557; available on arXiv at http://arxiv.org/abs/0810.4289v2.Google Scholar
[TW03]Tomanov, G. and Weiss, B.. Closed orbits for actions of maximal tori on homogeneous spaces. Duke Math. J. 119(2) (2003), 367392; MR 1997950(2004g:22006).Google Scholar