English

Classification of joinings for Kleinian groups

Dynamical Systems 2016-09-07 v2

Abstract

We classify all locally finite joinings of a horospherical subgroup action on \Gamma \ G when \Gamma is a Zariski dense geometrically finite subgroup of G=PSL_2(R) or PSL_2(C). This generalizes Ratner's 1983 joining theorem for the case when \Gamma is a lattice in G. One of the main ingredients is equidistribution of non-closed horospherical orbits with respect to the Burger-Roblin measure which we prove in a greater generality where G is the connected component of the identity in SO(n,1) for n at least 2 and \Gamma is any Zariski dense geometrically finite subgroup of G.

Keywords

Cite

@article{arxiv.1404.1510,
  title  = {Classification of joinings for Kleinian groups},
  author = {Amir Mohammadi and Hee Oh},
  journal= {arXiv preprint arXiv:1404.1510},
  year   = {2016}
}

Comments

57 pages, To appear in Duke Math. J

R2 v1 2026-06-22T03:43:50.978Z