Remarks on the Compatibility of Opposite Arrows of Time II

Ghenadie N. Mardari

The phenomenon of quantum erasure exposed a remarkable ambiguity in the interpretation of quantum entanglement. On the one hand, the data is compatible with the possibility of arrow-of-time violations. On the other hand, it is also possible that temporal non-locality is an artifact of post-selection. Twenty years later, this problem can be solved with a quantum monogamy experiment, in which four entangled quanta are measured in a delayed-choice arrangement. If Bell violations can be recovered from a “monogamous” quantum system, then the arrow of time is obeyed at the quantum level.

Francesco Mappa

Lawrence S. Schulman, M. G. E. da Luz

\n\nInteracting systems with opposite thermodynamic arrows are considered. From previous work on this topic it is known that each system will perceive the other as contributing to noise. However, it was not known whether such noise could be recognized as being due to an opposite-arrow system. We show here that there are signature properties of such interference. The observational implication is that opposite-arrow systems would be physically identifiable. The issue of signals passing between the systems is less well defined, but we show that with one interpretation of the signalling concept communication —but not conversational exchanges— could take place.\n

P. Morrison

Gerald F. Thomas

Sheldon Goldstein, Roderich Tumulka

We present a quantum model for the motion of N point particles, implying nonlocal (i.e., superluminal) influences of external fields on the trajectories, that is nonetheless fully relativistic. In contrast to other models that have been proposed, this one involves no additional spacetime structure as would be provided by a (possibly dynamical) foliation of spacetime. This is achieved through the interplay of opposite microcausal and macrocausal (i.e., thermodynamic) arrows of time.