Brief reply to "Can gravity account for the emergence of classicality?"

TL;DR

This paper defends previous findings that decoherence due to time dilation occurs in quantum systems with internal dynamics when superposed paths have different proper times, clarifying misconceptions raised by critics.

Contribution

The authors clarify and reaffirm their original results on decoherence caused by time dilation, addressing and correcting recent criticisms and misunderstandings.

Findings

Decoherence occurs when superposed paths have different proper times.

Criticisms based on the equivalence principle are addressed and refuted.

The physical prediction of decoherence due to time dilation remains valid.

Abstract

In a series of comments, Bonder et al. criticized our work on decoherence due to time dilation [Nature Physics 11, 668-672 (2015)]. First the authors erroneously claimed that our results contradict the equivalence principle, only to "resolve" the alleged conflict in a second note. The resolution - relativity of simultaneity - was already explained in our reply [arXiv:1508.03296], which Bonder et al. now essentially reiterate. The newly raised points were also already extensively clarified in our note. The physical prediction of our work remains valid: systems with internal dynamics decohere if the superposed paths have different proper times.