Goodrich, K.; Gustafson, K.; Misra, B. - In: Physica A: Statistical Mechanics and its Applications 102 (1980) 2, pp. 379-388
Koopman's Lemma states that if a flow Tt is measure preserving for a measure μ on a constant energy surface Ω, then the flow generates a one parameter family of unitary operators Ut on L2 (Ω, μ). We show here a converse, namely that under certain (physically motivated) conditions a unitary...