Actions of F infty whose II 1 factors and orbit equivalence relations have prescribed fundamental group - Mathematics > Operator AlgebrasReport as inadecuate




Actions of F infty whose II 1 factors and orbit equivalence relations have prescribed fundamental group - Mathematics > Operator Algebras - Download this document for free, or read online. Document in PDF available to download.

Abstract: We show that given any subgroup F of R + which is either countable or belongsto a certain -large- class of uncountable subgroups, there exist continuouslymany free ergodic probability measure preserving actions \sigma i of the freegroup with infinitely many generators such that their associated group measurespace II 1 factors M i and orbit equivalence relations R i have fundamentalgroup equal to F and with M i respectively R i stably non-isomorphic.Moreover, these actions can be taken so that R i has no outer automorphisms andany automorphism of M i is unitary conjugate to an automorphism that actstrivially on $L^\inftyX i \subset M i$.



Author: Sorin Popa, Stefaan Vaes

Source: https://arxiv.org/



DOWNLOAD PDF




Related documents