TY - BOOK AU - Kechris,Alexander S. ED - SpringerLink (Online service) TI - Topics in Orbit Equivalence T2 - Lecture Notes in Mathematics, SN - 9783540445081 AV - QA8.9-10.3 U1 - 511.3 23 PY - 2004/// CY - Berlin, Heidelberg PB - Springer Berlin Heidelberg KW - Mathematics KW - Harmonic analysis KW - Differentiable dynamical systems KW - Logic, Symbolic and mathematical KW - Topology KW - Mathematical Logic and Foundations KW - Real Functions KW - Dynamical Systems and Ergodic Theory KW - Abstract Harmonic Analysis N1 - Preface -- I. Orbit Equivalence -- II. Amenability and Hyperfiniteness -- III. Costs of Equivalence Relations and Groups -- References -- Index N2 - This volume provides a self-contained introduction to some topics in orbit equivalence theory, a branch of ergodic theory. The first two chapters focus on hyperfiniteness and amenability. Included here are proofs of Dye's theorem that probability measure-preserving, ergodic actions of the integers are orbit equivalent and of the theorem of Connes-Feldman-Weiss identifying amenability and hyperfiniteness for non-singular equivalence relations. The presentation here is often influenced by descriptive set theory, and Borel and generic analogs of various results are discussed. The final chapter is a detailed account of Gaboriau's recent results on the theory of costs for equivalence relations and groups and its applications to proving rigidity theorems for actions of free groups UR - http://dx.doi.org/10.1007/b99421 ER -