Time change and orbit equivalence in ergodic theory (Q1115986)

The main purpose of this paper is to show that two measure preserving continuous-time flows on Lebesgue probability spaces are orbit equivalent if and only if they can be transformed into isomorphic flows by means of a time change by an integrable additive cocycle. To this end classical results from \textit{H. Totoki} [Mem. Fac. Sci., Kyushu Univ., Ser. A 20, 27-55 (1966; Zbl 0185.391)] are recalled and presented together with some new proofs and new results.