Relaxed Bounds on the Dilaton Mass in a String Cosmology Scenario

TL;DR

This paper investigates how the spectrum of quantum dilaton fluctuations influences bounds on the dilaton mass in string cosmology, revealing that certain spectral conditions can relax these bounds and align them with supersymmetry and dark matter models.

Contribution

It introduces relaxed bounds on the dilaton mass based on the spectral behavior of quantum fluctuations in a string cosmology context.

Findings

Relaxed bounds on dilaton mass for growing fluctuation spectra

Compatibility with supersymmetry breaking models

Potential for dilaton dark matter dominance in the universe

Abstract

We discuss bounds on the dilaton mass, following from the cosmological amplification of the quantum fluctuations of the dilaton background, under the assumption that such fluctuations are dominant with respect to the classical background oscillations. We show that if the fluctuation spectrum grows with the frequency the bounds are relaxed with respect to the more conventional case of a flat or decreasing spectrum. As a consequence, the allowed range of masses may become compatible with models of supersymmetry breaking, and with a universe presently dominated by a relic background of dilaton dark matter.