English

Phenomenology of $\Lambda$-CDM model: a possibility of accelerating Universe with positive pressure

General Relativity and Quantum Cosmology 2011-01-25 v3 Cosmology and Nongalactic Astrophysics

Abstract

Among various phenomenological Λ\Lambda models, a time-dependent model Λ˙H3\dot \Lambda\sim H^3 is selected here to investigate the Λ\Lambda-CDM cosmology. Using this model the expressions for the time-dependent equation of state parameter ω\omega and other physical parameters are derived. It is shown that in H3H^3 model accelerated expansion of the Universe takes place at negative energy density, but with a positive pressure. It has also been possible to obtain the change of sign of the deceleration parameter qq during cosmic evolution.

Keywords

Cite

@article{arxiv.0711.0686,
  title  = {Phenomenology of $\Lambda$-CDM model: a possibility of accelerating Universe with positive pressure},
  author = {Saibal Ray and Maxim Khlopov and Utpal Mukhopadhyay and Partha Pratim Ghosh},
  journal= {arXiv preprint arXiv:0711.0686},
  year   = {2011}
}

Comments

16 Latex pages, 11 figures, Considerable modifications in the text; Accepted in IJTP