English

Constraints on Kinematic Model from Recent Cosmic Observations: SN Ia, BAO and Observational Hubble Data

Cosmology and Nongalactic Astrophysics 2009-07-24 v1

Abstract

In this paper, linear first order expansion of deceleration parameter q(z)=q0+q1(1a)q(z)=q_0+q_1(1-a) (M1M_1), constant jerk j=j0j=j_0 (M2M_2) and third order expansion of luminosity distance (M3M_3) are confronted with cosmic observations: SCP 307 SN Ia, BAO and observational Hubble data (OHD). Likelihood is implemented to find the best fit model parameters. All these models give the same prediction of the evolution of the universe which is undergoing accelerated expansion currently and experiences a transition from decelerated expansion to accelerated expansion. But, the transition redshift depends on the concrete parameterized form of the model assumed. M1M_1 and M2M_2 give value of transition redshift about zt0.6z_t\sim 0.6. M3M_3 gives a larger one, say zt1z_t\sim 1. The χ2/dof\chi^2/dof implies almost the same goodness of the models. But, for its badness of evolution of deceleration parameter at high redshift z>1z>1, M3M_3 can not be reliable. M1M_1 and M2M_2 are compatible with Λ\LambdaCDM model at the 2σ2\sigma and 1σ1\sigma confidence levels respectively. M3M_3 is not compatible with Λ\LambdaCDM model at 2σ2\sigma confidence level. From M1M_1 and M2M_2 models, one can conclude that the cosmic data favor a cosmological model having j0<1j_0<-1.

Keywords

Cite

@article{arxiv.0905.4552,
  title  = {Constraints on Kinematic Model from Recent Cosmic Observations: SN Ia, BAO and Observational Hubble Data},
  author = {Lixin Xu and Wenbo Li and Jianbo Lu},
  journal= {arXiv preprint arXiv:0905.4552},
  year   = {2009}
}

Comments

9 pages, 3 figures