Observational constraints on the accelerating universe in the framework of a 5D bounce cosmological model

In the framework of a five-dimensional (5D) bounce cosmological model, a useful function f(z) is obtained by giving a concrete expression of deceleration parameter q(z)=q_1+\dfracq_21+\ln (1+ z). Then using the obtained Hubble parameter H(z) according to the function f(z), we constrain the accelerating universe from recent cosmic observations: the 192 ESSENCE SNe Ia and the 9 observational H(z) data. The best fitting values of transition redshift z_T and current deceleration parameter q_0 are given as z_T = 0.65_ - 0.12^ + 0.25 and q_0 = - 0.76_ - 0.15^ + 0.15 (1\sigma ). Furthermore, in the 5D bounce model it can be seen that the evolution of equation of state (EOS) for dark energy w_\rm de can cross over -1 at about z=0.23 and the current value w_\rm 0de = - 1.15<- 1. On the other hand, by giving a concrete expression of model-independent EOS of dark energy w_\rm de , in the 5D bounce model we obtain the best fitting values z_T = 0.66_ - 0.08^ + 0.11 and q_0 = - 0.69_ - 0.10^ + 0.10 (1\sigma) from the recently observed data: the 192 ESSENCE SNe Ia, the observational H(z) data, the 3-year Wilkinson Microwave Anisotropy Probe (WMAP), the Sloan Digital Sky Survey (SDSS) baryon acoustic peak and the x-ray gas mass fraction in clusters.