Probing for dynamics of dark energy and curvature of universe with latest cosmological observations

We use the newly released 182 type Ia supernova data combined with the third-year Wilkinson Microwave Anisotropic Probe data (WMAP3) and large scale structure (LSS) information including SDSS and 2dFGRS to constrain the dark energy equation of state (EoS) as well as the curvature of universe ΩK. Using the full dataset of Cosmic Microwave Background (CMB) and LSS rather than the shift parameter and linear growth factor, we make a Markov Chain Monte Carlo (MCMC) global fit, while paying particular attention to the dark energy perturbation. Parameterizing the EoS as wDE(a)=w0+w1(1−a), we find the best fit of (w0,w1) is (−1.053,0.944) and for wDE(a)=w0+w1sin(32πln(a)), the best fit for (w0,w1) is (−1.614,−1.046). We find that a flat universe is a good approximation, namely, |ΩK|>0.06 has been excluded by 2σ yet the inclusion of ΩK can affect the measurement of DE parameters owing to their correlation and the present systematic effects of SNIa measurements.