Some computations of 1-cohomology groups and construction of non orbit equivalent actions
| dc.creator | Popa, Sorin | |
| dc.date | 2004-07-12 | |
| dc.date | 2005-04-29 | |
| dc.date.accessioned | 2026-07-07T05:10:13Z | |
| dc.date.available | 2026-07-07T05:10:13Z | |
| dc.description | For each group $G$ having an infinite normal subgroup with the relative property (T) (for instance $G = H \times K$ where $H$ is infinite with property (T) and $K$ is arbitrary), and any countable abelian group $Λ$ we construct free ergodic measure preserving actions $σ_Λ$ of $G$ on the probability space such that the 1'st cohomology group of $σ_Λ$, $H^1(σ_Λ)$, is equal to Char$(G) \times Λ$. We deduce that $G$ has uncountably many non stably orbit equivalent actions. We also calculate 1-cohomology groups and show existence of ``many'' non stably orbit equivalent actions for free products of groups as above. | |
| dc.description | 24 pages (final version, with slight additions and change of title on 09/20/04) | |
| dc.identifier | https://arxiv.org/abs/math/0407199 | |
| dc.identifier | http://arxiv.org/abs/math/0407199 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/71860 | |
| dc.subject | Operator Algebras | |
| dc.subject | Group Theory | |
| dc.subject | 46L55, 46L10, 46L40, 22D25, 22D40, 28D15 | |
| dc.title | Some computations of 1-cohomology groups and construction of non orbit equivalent actions | |
| dc.type | text |