Equation of State of Dark Matter after Planck Data

الأصل · EN

In this paper, we loosen the zero equation of state of dark matter to a constant wdm. By using the currently available cosmic observations which include the type-Ia supernovae, the baryon acoustic oscillation, the WiggleZ measurements of matter power spectrum and the cosmic microwave background radiation from the firs release of Planck dat through the Markov chain Monte Carlo method, we found the equation of state of dark matter in 3σ regions: wdm=0.000707₋₀.₀₀₀₇₄₇₋₀.₀₀₁₄₉₋₀.₀₀₁₉₆⁺⁰.⁰⁰⁰⁷⁴⁶⁺⁰.⁰⁰¹⁴⁶⁺⁰.⁰⁰¹⁹³. The difference of the minimum χ² between the ΛCDM and ΛwDM models is Δχ²min=0.446 for one extra model parameter wdm. Although the currently available cosmic observations favor the ΛwDM mildly, no significant deviation from the ΛCDM model is found in 1σ regions.