Type: Article
Publication Date: 2011-03-01
Citations: 56
DOI: https://doi.org/10.4007/annals.2011.173.2.5
We study periodic torus orbits on spaces of lattices.Using the action of the group of adelic points of the underlying tori, we define a natural equivalence relation on these orbits, and show that the equivalence classes become uniformly distributed.This is a cubic analogue of Duke's theorem about the distribution of closed geodesics on the modular surface: suitably interpreted, the ideal classes of a cubic totally real field are equidistributed in the modular 5-fold SL 3 (Z)\SL 3 (R)/SO 3 .In particular, this proves (a stronger form of) the folklore conjecture that the collection of maximal compact flats in SL 3 (Z)\SL 3 (R)/SO 3 of volume ≤ V becomes equidistributed as V → ∞.The proof combines subconvexity estimates, measure classification, and local harmonic analysis.1 It is also conceivable that an ergodic approach to these estimates may exist.