2006/10/18 by Patrick Peter, E. J. C. Pinho, Nelson Pinto-Neto · 1 citation
Physics and Astronomy · #hep-th #astro-ph #gr-qc #hep-ph
paper · pdf · doi:10.1103/physrevd.75.023516
published as Phys.Rev.D75:023516,2007 · 9 pages, 4 figures
arxiv created 2006/10/18 · arxiv updated 2009/12/01
We show that a contracting universe which bounces due to quantum cosmological effects and connects to the hot big-bang expansion phase, can produce an almost scale invariant spectrum of perturbations provided the perturbations are produced during an almost matter dominated era in the contraction phase. This is achieved using Bohmian solutions of the canonical Wheeler-de Witt equation, thus treating both the background and the perturbations in a fully quantum manner. We find a very slightly blue spectrum (nS-1>0). Taking into account the spectral index constraint as well as the CMB normalization measure yields an equation of state that should be less than ω\lesssim 8× 10-4, implying nS-1 ∼ O(10-4), and that the characteristic size of the Universe at the bounce is L0 ∼ 103 ℓPlanck, a region where one expects that the Wheeler-DeWitt equation should be valid without being spoiled by string or loop quantum gravity effects.