1999/06/10 by Chung-Pei Ma, R. R. Caldwell, Paul Bode +1 · 4 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Cold dark matter #Cosmological constant #Cosmology #Cosmology and Gravitation Theories #Dark energy #Equation of state #Galaxies: Formation, Evolution, Phenomena #Lambda-CDM model #Matter power spectrum #Nonlinear system #Quintessence #Spectral density #astro-ph #hep-ph
paper · pdf · doi:10.1086/312183
published as Astrophys.J. 521 (1999) L1-L4 · 5 pages with 3 inserted postscript figures, AAS LaTeX v4.0 emulateapj.sty. Astrophysical Journal Letters, in press
arxiv created 1999/06/10 · openalex publication_date 1999/08/10 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present simple analytic approximations for the linear and fully evolved nonlinear mass power spectrum for spatially flat cold dark matter (CDM) cosmological models with quintessence (Q). Quintessence is a time evolving, spatially inhomogeneous energy component with negative pressure and an equation of state wQ < 0. It clusters gravitationally on large length scales but remains smooth like the cosmological constant on small length scales. We show that the clustering scale is determined by the Compton wavelength of the Q-field and derive a shape parameter, ΓQ, to characterize the linear mass power spectrum. The growth of linear perturbations as functions of redshift, wQ, and matter density Ωm is also quantified. Calibrating to N-body simulations, we construct a simple extension of the formula by Ma (1998) that closely approximates the nonlinear power spectrum for a range of plausible QCDM models.