A lower bound for the velocity of quantum communications in the preferred frame

TL;DR

This study tests the existence of a preferred frame for superluminal quantum communication signals by analyzing entangled photon correlations over 21 days, finding that such signals must travel faster than approximately 6,000 times the speed of light if a preferred frame exists.

Contribution

The paper provides experimental lower bounds on the velocity of hypothetical superluminal signals in a preferred frame, constraining models of quantum nonlocality involving superluminal communication.

Findings

No deviation from Quantum Theory predictions observed.

Superluminal communication velocity must exceed ~6,000 c if a preferred frame exists.

Constraints apply for any arbitrary direction of the preferred frame velocity.

Abstract

An EPR experiment with polarized entangled photons is performed to test the Eberhard model. According to the Eberhard model, quantum correlations between space-like separated events are due to a superluminal communication signal propagating in a preferred frame. The coincidences between entangled photons passing through two polarizers aligned along a East-West axis are measured as a function of time during 21 sidereal days. No deviation from the predictions of the Quantum Theory is observed. Tacking into account for the experimental uncertainties, we infer that, if a preferred frame for superluminal signals exists which moves at velocity \vec{v} with respect to the Earth, the modulus of the velocity of quantum communications in this frame has to be greater than v_{t}~0.6*10^4 c for v<0.1 c and for any arbitrary direction of \vec{v}.