A property (T) free proof of Gaboriau-Popa
by Professor Greg Hjorth
Abstract: Gaboriau and Popa showed that a non-abelian free group has continuum many actions of a certain kind up to Orbit Equivalence. Their argument, and the related arguments in the following years, used the notion of property (T). I will sketch a far more elementary proof, which uses almost nothing beyond dynamics and topology.
For More Information: contact: Greg Hjorth. email G.Hjorth@ms.unimelb.edu.au