Superluminal motion in (semi)classical relativity

TL;DR

This paper explores the theoretical possibility of superluminal motion of non-tachyonic bodies within general relativity, examining quantum field theory constraints and identifying conditions where such motion might occur.

Contribution

It analyzes conditions under which superluminal motion could occur in (semi)classical relativity, highlighting cases where quantum field theory does not prohibit such motion.

Findings

Quantum field theory can prohibit superluminal motion in some cases.

Superluminal motion is not universally forbidden in general relativity.

Certain conditions allow for superluminal motion without tachyons.

Abstract

The possibility is discussed of superluminal motion of non-tachyonic (i.e. moving with the instantaneous speed v<c) bodies within general relativity. It is shown that in some occasions quantum field theory apparently prohibits such motion, but not - to all appearance - in the general case.