Scalar perturbations in string-dilaton cosmology

Abstract

Scalar perturbative potentials are constructed on exact background solutions for string-dilaton cosmology. We deal with the string effective Lagrangian under the same standard of an Induced Gravity Theory non-minimally coupled with a scalar field (the dilaton) and apply the theory of gauge-invariant perturbations. The main results are that we are able to obtain density contrasts (δρ/ρ) which can be connected with the observations and to control the horizon crossing for the perturbation scales.