2000/07/06 by Vinod B. Johri, V. B. Johri, Johri, Vinod B.
Computer Science · Physics and Astronomy · #Astrophysics (astro-ph) #Computational Physics and Python Applications #Cosmology and Gravitation Theories #FOS: Physical sciences #Relativity and Gravitational Theory #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0007079
12 pages, Latex file, 4 figures, typos corrected
openalex publication_date 2000/07/06 · arxiv created 2001/05/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A brief account of the current cosmological observations is given and their implications for QCDM and ΛCDM cosmologies are discussed. The nucleosynthesis and the galaxy formation constraints have been used to put limits on Ωϕ during cosmic evolution, and develop a realistic approach to the tracking behaviour of quintessence fields. The astrophysical constraints are applied to interpolate the value of the tracking parameter ε≃ 0.75 at the present epoch and also to find the lower and the upper limits for Λ in the accelerating universe. It is shown that the transition from deceleration to acceleration in the cosmic expansion occurs earlier in ΛCDM cosmology compared to QCDM cosmology.