We comment on statements made about quantum representation theory in the paper by T. W. Marshall and E. Santos [Phys. Rev. A 41, 1582 (1990)]. Results are presented which show that correct results can be obtained from Langevin equations derived from the positive-P representation, even when those obtained by truncation of the Wigner time-evolution equation give incorrect results.
- Received 25 June 1990
©1991 American Physical Society