Widom, Srivastava, and Sassaroli have published [Phys. Lett. A 203, 255 (1995)] a calculation which purports to show that "future events can affect present events". In this note an error in their calculation is identified.
Coherence in an atom interferometer - longitudinal and transverse, D. Pritchard a fully quantum treatment of molecular beam resonance - creation and detection of longitudinal momentum coherences, R.A. Rubenstein coherence of Bose-condensates in atomic gases, M.R. Andrews neutrino oscillations - a two-level system example, E. Sassaroli coherence and fluctuations in particle-field interactions, B.L. Hu time crystals, Y. Srivastava Greenberger-Horne-Zellinger experiment on mixed states, S. Lloyd Einstein acausality with application to laboratory systems, A. Widom. (Part contents).
The reviewers contacted by the editors to evaluate this work have been unable to confirm that the main results are correct. Flaws that were identified by the reviewers in earlier versions of the paper have been addressed by the author. Although it is possible that future research will uncover a significant mistake in this paper or show that the conclusions are in error, I believe that publishing it may benefit the readership of the Journal and stimulate further work in mathematical physics on an important topic.