ﻻ يوجد ملخص باللغة العربية
Let $G$ be a subgroup of $text{Homeo}_+(mathbb{R})$ without crossed elements. We show the equivalence among three items: (1) existence of $G$-invariant Radon measures on $mathbb R$; (2) existence of minimal closed subsets of $mathbb R$; (3) nonexistence of infinite towers covering the whole line. For a nilpotent subgroup $G$ of $text{Homeo}_+(mathbb{R})$, we show that $G$ always has an invariant Radon measure and a minimal closed set if every element of $G$ is $C^{1+alpha} (alpha>0$); a counterexample of $C^1$ commutative subgroup of $text{Homeo}_+(mathbb{R})$ is constructed.
Let $text{Homeo}_{+}(mathbb{S}^1)$ denote the group of orientation preserving homeomorphisms of the circle $mathbb{S}^1$. A subgroup $G$ of $text{Homeo}_{+}(mathbb{S}^1)$ is tightly transitive if it is topologically transitive and no subgroup $H$ of
We consider random walks on the group of orientation-preserving homeomorphisms of the real line ${mathbb R}$. In particular, the fundamental question of uniqueness of an invariant measure of the generated process is raised. This problem was already s
We prove some ergodic-theoretic rigidity properties of the action of SL(2,R) on moduli space. In particular, we show that any ergodic measure invariant under the action of the upper triangular subgroup of SL(2,R) is supported on an invariant affine s
We consider the action of $SL(2,mathbb{R})$ on a vector bundle $mathbf{H}$ preserving an ergodic probability measure $ u$ on the base $X$. Under an irreducibility assumption on this action, we prove that if $hat u$ is any lift of $ u$ to a probabilit
In this note, we give a nature action of the modular group on the ends of the infinite (p + 1)-cayley tree, for each prime p. We show that there is a unique invariant probability measure for each p.