Relatively perfect σ-algebras for flows
Volume 114 / 1995
Studia Mathematica 114 (1995), 71-85
DOI: 10.4064/sm-114-1-71-85
Abstract
We show that for every ergodic flow, given any factor σ-algebra ℱ, there exists a σ-algebra which is relatively perfect with respect to ℱ. Using this result and Ornstein's isomorphism theorem for flows, we give a functorial definition of the entropy of flows.
