2004/09/07 by Vinod B. Johri, V. B. Johri, Johri, Vinod B.
Earth and Planetary Sciences · Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #Cosmology and Gravitation Theories #FOS: Physical sciences #Geophysics and Gravity Measurements #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0409161
7 pages, no figures, references added
openalex publication_date 2004/09/07 · arxiv created 2004/09/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A comparative study of various parametrizations of the dark energy equation of state w(z) and its variation with the redshift is made. Astrophysical constraints from 'integrated tracking' are laid down to test the physical viability and cosmological compatibility of these parametrizations. A critical evaluation of the 4-index Hannestad parametrization is done. It is found to be simple and transparent in probing the evolution of the dark energy during the expansion history of the universe but it does not satisfy the BBN constraint on the dark energy density parameter for the best fit values; however it looks more compatible with the observations in the extended parameter space with w<< -1.