In this paper , we combine the latest observational data , including the WMAP five-year data ( WMAP5 ) , BOOMERanG , CBI , VSA , ACBAR , as well as the Baryon Acoustic Oscillations ( BAO ) and Type Ia Supernoave ( SN ) “ Union ” compilation ( 307 sample ) , and use the Markov Chain Monte Carlo method to determine the cosmological parameters , such as the equation-of-state ( EoS ) of dark energy , the curvature of universe , the total neutrino mass and the parameters associated with the power spectrum of primordial fluctuations .
Our results show that the \Lambda CDM model remains a good fit to the current data .
In a flat universe , we obtain the tight limit on the constant EoS of dark energy as , w = -0.977 \pm 0.056 ( 1 ~ { } \sigma ) .
For the dynamical dark energy models with time evolving EoS parameterized as w _ { { \mathrm { de } } } ( a ) = w _ { 0 } + w _ { 1 } ( 1 - a ) , we find that the best-fit values are w _ { 0 } = -1.08 and w _ { 1 } = 0.368 , implying the preference of Quintom model whose EoS gets across the cosmological constant boundary during evolution .
For the curvature of universe \Omega _ { k } , our results give -0.012 < \Omega _ { k } < 0.009 ( 95 \% C.L . )
when fixing w _ { { \mathrm { de } } } = -1 .
When considering the dynamics of dark energy , the flat universe is still a good fit to the current data , -0.015 < \Omega _ { k } < 0.018 ( 95 \% C.L . ) .
Regarding the neutrino mass limit , we obtain the upper limits , \sum m _ { \nu } < 0.533 eV ( 95 \% C.L . )
within the framework of the flat \Lambda CDM model .
When adding the SDSS Lyman- \alpha forest power spectrum data , the constraint on \sum m _ { \nu } can be significantly improved , \sum m _ { \nu } < 0.161 eV ( 95 \% C.L . ) .
However , these limits can be weakened by a factor of 2 in the framework of dynamical dark energy models , due to the obvious degeneracy between neutrino mass and the EoS of dark energy model .
Assuming that the primordial fluctuations are adiabatic with a power law spectrum , within the \Lambda CDM model , we find that the upper limit on the ratio of the tensor to scalar is r < 0.200 ( 95 \% C.L . )
and the inflationary models with the slope n _ { s } \geq 1 are excluded at more than 2 ~ { } \sigma confidence level .
However , in the framework of dynamical dark energy models , the allowed region in the parameter space of ( n _ { s } , r ) is enlarged significantly .
Finally , we find no strong evidence for the large running of the spectral index , \alpha _ { s } = -0.019 \pm 0.017 ( 1 ~ { } \sigma ) for the \Lambda CDM model and \alpha _ { s } = -0.023 \pm 0.019 ( 1 ~ { } \sigma ) for the dynamical dark energy model , respectively .