2008/08/31 by Robert J. Scherrer, Anjan A. Sen, A. A. Sen · 2 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #High-Energy Particle Collisions Research #astro-ph #gr-qc
paper · pdf · doi:10.1103/physrevd.78.067303
published as Phys.Rev.D78:067303,2008 · 4 pages, 2 figures, discussion added, to appear in Phys. Rev. D
arxiv created 2008/09/11 · openalex publication_date 2008/09/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We examine phantom dark energy models produced by a field with a negative kinetic term and a potential that satisfies the slow-roll conditions: [(1/V)(dV/d\ensuremathφ)]2\ensuremath≪1 and (1/V)(d2V/d\ensuremathφ2)\ensuremath≪1. Such models provide a natural mechanism to produce an equation of state parameter, w, slightly less than \ensuremath-1 at present. Using techniques previously applied to quintessence, we show that in this limit, all such phantom models converge to a single expression for w(a), which is a function only of the present-day values of \ensuremathΩ_\ensuremathφ and w. This expression is identical to the corresponding behavior of w(a) for quintessence models in the same limit. At redshifts z\ensuremath\lesssim1, this limiting behavior is well fit by the linear parametrization, w=w0+wa(1\ensuremath-a), with wa\ensuremath≈\ensuremath-1.5(1+w0).