Primordial perturbations from slow-roll inflation on a brane

Kazuya Koyama, Andrew Mennim, V. A. Rubakov, David Wands, Takashi Hiramatsu

Submitted on 26 January 2007


In this paper we quantise scalar perturbations in a Randall-Sundrum-type model of inflation where the inflaton field is confined to a single brane embedded in five-dimensional anti-de Sitter space-time. In the high energy regime, small-scale inflaton fluctuations are strongly coupled to metric perturbations in the bulk and gravitational back-reaction has a dramatic effect on the behaviour of inflaton perturbations on sub-horizon scales. This is in contrast to the standard four-dimensional result where gravitational back-reaction can be neglected on small scales. Nevertheless, this does not give rise to significant particle production, and the correction to the power spectrum of the curvature perturbations on super-horizon scales is shown to be suppressed by a slow-roll parameter. We calculate the complete first order slow-roll corrections to the spectrum of primordial curvature perturbations.


Comment: 23 pages, 10 figures

Subjects: High Energy Physics - Theory; Astrophysics; General Relativity and Quantum Cosmology; High Energy Physics - Phenomenology