Exact spectrum of scalar field perturbations in a radiation deformed closed de Sitter universe
arXiv:hep-th/0611277 · doi:10.1088/1475-7516/2007/03/002
Abstract
We observe that the equation of motion for a free scalar field in a closed universe with radiation and a positive cosmological constant is given by Lamé's equation. Computing the exact power spectrum of scalar field perturbations, the presence of both curvature and radiation produces a red tilt weakly dependent on the amount of radiation.
16 pages, 2 figures