Dynamical Instability of Self-Tuning Solution with Antisymmetric Tensor Field

TL;DR

This paper investigates the stability of a brane model with an antisymmetric tensor field, revealing that the static solution is unstable under gravitational perturbations, indicating potential fine-tuning issues.

Contribution

It demonstrates the dynamical instability of a self-tuning brane solution involving an antisymmetric tensor field, highlighting challenges in achieving stable self-tuning solutions.

Findings

Existence of time-dependent gravitational perturbations

Static solution is an unstable saddle point

Implication of hidden fine tuning in the model

Abstract

We consider the dynamical stability of a static brane model that incorporates a three-index antisymmetric tensor field and has recently been proposed as a possible solution to the cosmological constant problem. Ultimately, we are able to establish the existence of time-dependent, purely gravitational perturbations. As a consequence, the static solution of interest is ``dangerously'' located at an unstable saddle point. This outcome is suggestive of a hidden fine tuning in what is an otherwise self-tuning model.