Release Time:2019-03-09  Hits:

Indexed by: Journal Papers

Date of Publication: 2010-06-28

Journal: PHYSICS LETTERS B

Included Journals: SCIE

Volume: 690

Issue: 4

Page Number: 333-336

ISSN: 0370-2693

Key Words: Time variable cosmological constant; Dark energy

Abstract: In this Letter, time variable cosmological constant, dubbed age cosmological constant, is investigated motivated by the fact: any cosmological length scale and time scale can introduce a cosmological constant or vacuum energy density into Einstein's theory. The age cosmological constant takes the form rho(A) = 3c(2)M(P)(2)/t(A)(2), where t(A) is the age or conformal age of our universe. The effective equation of state (EoS) of age cosmological constant are w(A)(eff) = -1 + 2/3 root Omega A/c and w(A)(eff) = -1 + 2/3 root Omega A/c(1+z) when the age and conformal age of universe are taken as the role of cosmological time scales respectively. The EoS are the same as the so-called agegraphic dark energy models. However, the evolution histories are different from the agegraphic ones for their different evolution equations. (C) 2010 Elsevier B.V. All rights reserved.