A note on minimal models for pmp actions.

Given a countable group G, we say that a metrizable flow Y is model-universal if by considering the various invariant measures on Y, we can recover every free measure-preserving G-system up to isomorphism. Weiss in[ Dynamical systems and group actions , American Mathematical Society, Providence, RI, 2012, pp. 249-264] constructs a minimal model-universal flow. In this note, we provide a new, streamlined construction, allowing us to show that a minimal model-universal flow is far from unique. [ABSTRACT FROM AUTHOR]