Invariant measures and orbit closures for unipotent actions on homogeneous spaces (Q1321629)

A survey paper concerning mainly the author's results about the action of a unipotent subgroup \(U\) of a connected Lie group \(G\) on a homogeneous space \(G/\Gamma\), where \(\Gamma\) is a discrete subgroup of \(G\). The results were published in a series of papers beginning in 1990. Some new extensions, as well as applications to ergodic theory and number theory, are also discussed.