Linear Cosmological Perturbations in D-brane Gases

TL;DR

This paper investigates linear cosmological perturbations in a D-brane gas model with stabilized compact dimensions and dilaton, demonstrating the absence of instabilities and supporting the stability of the model.

Contribution

It shows that D-brane gas models remain stable under linear inhomogeneities, with internal space perturbations damping over time.

Findings

No instabilities found in long wavelength perturbations.

Internal space perturbations decay as damped oscillations.

Stabilization mechanism remains valid with inhomogeneities.

Abstract

We consider linear cosmological perturbations on the background of a D-brane gas in which the compact dimensions and the dilaton are stabilized. We focus on long wavelength fluctuations and find that there are no instabilities. In particular, the perturbation of the internal space performs damped oscillations and decays in time. Therefore, the stabilization mechanism based on D-brane gases in string theory remains valid in the presence of linearized inhomogeneities.