ar X iv : 0 71 1 . 06 86 v 1 [ gr - q c ] 5 N ov 2 00 7 Phenomenology of Λ - CDM model : a possibility of accelerating Universe with positive pressure
نویسندگان
چکیده
Among various phenomenological Λ models, a time-dependent model Λ̇ ∼ H is selected here to investigate the Λ-CDM cosmology. Using this model the expressions for the time-dependent equation of state parameter ω and other physical parameters are derived. It is shown that in H 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 q during cosmic evolution.
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