Eur. Phys. J. C (2010) 65: 295-301
https://doi.org/10.1140/epjc/s10052-009-1180-2

Regular Article - Theoretical Physics

Scale-invariant scalar metric fluctuations during inflation: non-perturbative formalism from a 5D vacuum

¹ Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes, 3350, C.P. 7600, Mar del Plata, Argentina
² Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Funes 3350, C.P. 7600, Mar del Plata, Argentina
³ Departamento de Física, DCI, Campus León, Universidad de Guanajuato, C.P. 37150, León Guanajuato, México

^* e-mail: mbellini@mdp.edu.ar

Received: 20 July 2009
Published online: 31 October 2009

Abstract

We extend to 5D an approach of a 4D non-perturbative formalism to study scalar metric fluctuations of a 5D Riemann-flat de Sitter background metric. In contrast with the results obtained in 4D, the spectrum of cosmological scalar metric fluctuations during inflation can be scale invariant and the background inflaton field can take sub-Planckian values.