Cascading Gravity and Degravitation

TL;DR

This paper introduces a cascading brane gravity model that transitions from higher to lower dimensions at different scales, enabling degravitation of the cosmological constant while remaining ghost-free and consistent.

Contribution

It presents a novel cascading brane model that interpolates gravity across dimensions and demonstrates its ghost-free nature and potential for addressing the cosmological constant problem.

Findings

Model interpolates gravity from (n+4) to 4 dimensions across scales.

The model is shown to be ghost free with appropriate brane operators.

Provides a promising IR modification of gravity for cosmological constant degravitation.

Abstract

We construct a cascading brane model of gravity in which the behavior of the gravitational force law interpolates from (n+4)-dimensional to (n+3)-dimensional all the way down to 4-dimensional from longer to shorter length scales. We show that at the linearized level, this model exhibits the features necessary for degravitation of the cosmological constant. The model is shown to be ghost free with the addition of suitable brane kinetic operators, and we demonstrate this using a number of independent procedures. Consequently this is a consistent IR modification of gravity, providing a promising framework for a dynamical, degravitating solution of the cosmological constant problem.