Release Time:2019-03-10  Hits:

Indexed by: Journal Article

Date of Publication: 2008-07-30

Journal: MODERN PHYSICS LETTERS A

Included Journals: Scopus、SCIE

Volume: 23

Issue: 23

Page Number: 1939-1948

ISSN: 0217-7323

Key Words: dark energy; decelerated parameter; transition redshift

Abstract: In this paper, two simple parametrized deceleraton parameters q(z) = a + bz/1+z and q(z) = a + b/1+1n(1+z) are constrained by using SNe Ia Gold dataset, observational Hubble data and their combination. It is found that the transition redshift from decelerated expansion to accelerated expansion zT and current decelerated parameter values q0 are consistent with each other in 1 sigma region by only SNe Ia Gold dataset and observational Hubble data in three parametrizations respectively. By combining the SNe Ia Gold dataset and observational Hubble data together, a tight constraint is obtained. With this combined constraint, zT is 0.56(-0.09)(+0.18) and 0.54(- 0.09)(+0.19) with 1 sigma error in the parametrizations respectively.