1998/09/30 by David Wands · 2 citations
Physics and Astronomy · #Advanced Differential Geometry Research #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.60.023507
published as Phys.Rev. D60 (1999) 023507 · 5 pages, Latex with Revtex. Hamiltonian formulation added and discussion expanded. Version to appear in Phys Rev D
arxiv created 1999/04/21 · openalex publication_date 1999/06/11 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
I show that cosmological perturbation spectra produced from quantum fluctuations in massless or self-interacting scalar fields during an inflationary era remain invariant under a two parameter family of transformations of the homogeneous background fields. This relates slow-roll inflation models to solutions which may be far from the usual slow-roll limit. For example, a scale-invariant spectrum of perturbations in a minimally coupled, massless field can be produced by an exponential expansion with a\ensuremath∝eHt, or by a collapsing universe with a\ensuremath∝(\ensuremath-t)2/3.