Relativity accommodates superluminal mean velocities

TL;DR

This paper explains that velocity measurements can exceed the speed of light without violating relativity, but these effects are too small to account for the OPERA superluminal neutrino claim, which remains unexplained.

Contribution

It clarifies how superluminal velocities can occur within relativity and analyzes potential effects on OPERA neutrinos, ruling out known relativistic explanations.

Findings

Velocity measures can exceed c without contradicting relativity.

Relativistic effects cannot explain the OPERA superluminal neutrino result.

The observed superluminal velocities are too small to be explained by known effects.

Abstract

Contrary to a widespread belief, measures of velocity can yield a value larger than $c$, the instantaneous light speed in vacuum, without contradicting Einstein's relativity. Nevertheless, the effect turns out to be too small to explain the recently claimed superluminal velocity by the OPERA collaboration. Several other general relativistic effects acting on the OPERA neutrinos are also analyzed. All of them are unable to explain the OPERA result.