A Bit Rate Bound on Superluminal Communication

TL;DR

This paper derives a theoretical upper limit on the rate of superluminal information transfer in certain scalar field theories that violate positivity, highlighting fundamental constraints on faster-than-light communication.

Contribution

It introduces a novel bit rate bound for superluminal communication in positivity-violating k-essence theories, applicable to a broad class of such models.

Findings

A new bound on superluminal communication rate

Implication that maximal information speed may not exist

Constraints arise from non-linear self-interactions

Abstract

We study semi-classical communication in positivity-violating k-essence scalar field theories, with superluminal modes propagating on a rolling background. The self-interactions due to the non-linear nature of these theories pose a constraint on the rate of superluminal information transfer. We derive a novel bit rate bound on superluminal communication within a conceptual model, to which a general class of k-essence theories naturally reduces. Our result implies the possibility that, even if these positivity-violating k-essence theories may not possess a maximal information propagation speed, there is nevertheless an upper bound on the rate of information transfer.