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Indexed by:期刊论文

Date of Publication:2011-08-11

Journal:PHYSICS LETTERS B

Included Journals:SCIE

Volume:702

Issue:2-3

Page Number:114-120

ISSN No.:0370-2693

Key Words:Cosmography

Abstract:In this Letter, a parametrization describing the kinematical state of the universe via cosmographic approach is considered, where the minimum input is the assumption of the cosmological principle, i.e. the Friedmann-Robertson-Walker metric. A distinguished feature is that the result does not depend on any gravity theory and dark energy models. As a result, a series of cosmographic parameters (deceleration parameter q(0), jerk parameter j(0) and snap parameter s(0)) are constrained from the cosmic observations which include type la supernovae (SN) Union2, the Baryon Acoustic Oscillation (BAD), the observational Hubble data (OHD), the high redshift Gamma ray bursts (GRBs). By using Markov Chain Monte Carlo (MCMC) method, we find the best fit values of cosmographic parameters in 1 sigma regions: H-0 = 74.299(-4.287)(+4.932), q(0) = -0.386(-0.618)(+0.655), j(0) = -4.925(-7.297)(+6.658) and s(0) = -26.404(-9.097)(+20.964) which are improved remarkably. The values of q(0) and j(0) are consistent with flat Lambda CDM model in 1 sigma region. But the value of S-0 of flat Lambda CDM model will go beyond the 1 sigma region. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.