The red-shift space distortions in the galaxy power spectrum can be used to measure the growth rate of matter density perturbations δm. For dynamical dark energy models in General Relativity we provide a convenient analytic formula of f(z)σ8 (z) written as a function of the redshift z, where f = dln δm/dln a (a is the cosmological scale factor) and σ8 is the rms amplitude of over-density at the scale 8 h-1 Mpc. Our formula can be applied to the models of imperfect fluids, quintessence, and k-essence, provided that the dark energy equation of state w does not vary significantly and that the sound speed is not much smaller than 1. We also place observational constraints on dark energy models of constant w and tracking quintessence from the recent data of red-shift space distortions.
ASJC Scopus subject areas
- Astronomy and Astrophysics