Lorentz violation and red shift of gravitational waves in brane-worlds

TL;DR

This paper investigates how extra dimensions in brane-world models can cause Lorentz violation and alter the red shift of gravitational waves, providing potential signatures for detecting extra dimensions.

Contribution

It demonstrates that space-like extra dimensions lead to faster gravitational wave speeds in the bulk and compares their red shift with electromagnetic waves to identify observable signatures.

Findings

Gravitational waves travel faster in the bulk than on the brane with space-like extra dimensions.

Lorentz invariance is broken in the gravitational sector due to extra dimensions.

Red shift differences between gravitational and electromagnetic waves can reveal extra-dimensional effects.

Abstract

In this paper we study the speed of gravitational waves in a brane world scenario and show that if the extra dimension is space-like, the speed of the propagation of such waves is greater in the bulk than that on the brane. Therefore, the 4D Lorentz invariance is broken in the gravitational sector. A comparison is also made between the red shift of such waves and those of the electromagnetic waves on the brane. Such a comparison is essential for extracting the signature of the extra dimension and thus clarifying the question of maximal velocity of gravitational waves in the bulk.