Abstract
In [1] G. Margulis proved Ghys's conjecture stating the validity of the following analog of the Tits alternative: either the group \(G \subseteq {\text{Homeo}}(S^1 )\) of homeomorphisms of the circle possesses a free subgroup with two generators or there is an invariant probabilistic measure on S 1. In the present paper, we prove the following strengthening of Margulis's statement: an invariant probabilistic measure for a group \(G \subseteq {\text{Homeo}}(S^1 )\) exists if and only if the quotient group \(G/H_G \) does not contain a free subgroup with two generators (here \(H_G \) is some specific subgroup of G defined in a canonical way). We also formulate and prove analogs of the Tits alternative for groups \(G \subseteq {\text{Homeo}}(\mathbb{R})\) of homeomorphisms of the line.
Similar content being viewed by others
REFERENCES
G. Margulis, “Free subgroups of the homeomorphism group of the circle,” C.R. Acad. Sci. Paris. Ser. I, 331 (2000), 669–674.
L. A. Beklaryan, “On the classification problem for groups of orientation preserving homeomorphisms of ℝ. III. ω-projectively invariant measures,” Mat. Sb. [Russian Acad. Sci. Sb. Math.], 190 (1999), no. 4, 43–62.
V. V. Solodov, “Homeomorphisms of the circle and foliations,” Izv. Akad. Nauk SSSR Ser. Mat. [Math. USSR-Izv.], 48 (1984), no. 3, 599–613.
V. V. Solodov, “Homeomorphisms of the line and foliations,” Izv. Akad. Nauk SSSR Ser. Mat. [Math. USSR-Izv.], 46 (1982), no. 5, 1047–1060.
L A. Beklaryan, “On the classification problem for groups of orientation preserving homeomorphisms of ℝ II. Projectively invariant measures,” Mat. Sb. [Russian Acad. Sci. Sb. Math.], 187 (1996), no. 4, 3–28.
L. A. Beklaryan, “On the classification problem for groups of orientation preserving homeomorphisms of ℝ. I. Invariant measures,” Mat. Sb. [Russian Acad. Sci. Sb. Math.], 187 (1996), no. 3, 23–54.
L. A. Beklaryan, “The structure of the quotient group of the group of orientation preserving homeomorphisms of ℝ modulo the subgroup generated by the union of stabilizers,” Dokl. Ross. Akad. Nauk [Russian Acad. Sci. Dokl. Math.], 331 (1993), no. 2, 137–139.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Beklaryan, L.A. On Analogs of the Tits Alternative for Groups of Homeomorphisms of the Circle and of the Line. Mathematical Notes 71, 305–315 (2002). https://doi.org/10.1023/A:1014890606194
Issue Date:
DOI: https://doi.org/10.1023/A:1014890606194