In this paper we show that there are “E0 many” orbit inequivalent free actions of the free groups 𝔽n, 2≮ n≮∞ by measure preserving transformations on a standard Borel probability space. In particular, there are uncountably many such actions.
"Orbit equivalence and actions of 𝔽n." J. Symbolic Logic 71 (1) 265 - 282, March 2006. https://doi.org/10.2178/jsl/1140641174