A braneworld model in a massive gravity

TL;DR

This paper constructs a Randall-Sundrum-like braneworld model within a 5D Lorentz-violating massive gravity framework, addressing the gauge hierarchy problem and analyzing perturbations, revealing stable tensor and vector modes but a ghost scalar mode.

Contribution

It introduces a novel 5D braneworld model in Lorentz-violating massive gravity, solving the hierarchy problem and analyzing perturbations with stability considerations.

Findings

Tensor and vector perturbations are stable and ghost-free.

Scalar perturbation is identified as a ghost field.

Mass spectra of modes show TeV-scale splitting and propagation along the brane.

Abstract

A Randall-Sundrum-like braneworld scenario is constructed in a 5D extension of the Lorentz-violating massive gravity. The gauge hierarchy problem is solved in current model. The linear perturbations are calculated, and it is found that the tensor and vector perturbations are robust and free from the ghost and tachyonic instabilities, however, the scalar perturbation is a ghost filed. After Kaluza-Klein reduction, all the tensor, vector and scalar modes are massive and possess the mass splitting of order of TeV in their respective mass spectra. The massive ground states of tensor and scalar modes propagate only along the brane, however, the vector ground state is absent in the mass spectrum. By introducing the Goldberger-Wise mechanism to stabilize the extra dimension, the 4D effective theory on the brane includes a nearly massless graviton plus three towers of very massive spin-2, spin-1 and ghost spin-0 particles.