Observational tests of x-matter models |
| |
| Authors: | Takeshi Chiba Naoshi Sugiyama & Takashi Nakamura |
| |
| Institution: | Department of Physics, University of Tokyo, Tokyo 113-0033, Japan,;Department of Physics, Kyoto University, Kyoto 606-8502, Japan,;Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan |
| |
| Abstract: | We study gravitational lensing statistics, matter power spectra and the angular power spectra of the cosmic microwave background (CMB) radiation in x-matter models. We adopt an equation of state of x-matter which can express a wide range of matter from pressureless dust to the cosmological constant. A new ingredient in this model is the sound speed of the x-component, in addition to the equation of state w 0 = p x0/ρx0. Except for the cosmological constant case, the perturbations of x-matter itself are considered. Our primary interest is in the effect of non-zero sound speed on the structure formation and the CMB spectra. It is found that there exist parameter ranges where x-matter models are consistent with all current observations. The x-matter generally leaves imprints in the CMB anisotropy and the matter power spectrum, which should be detectable in future observations. |
| |
| Keywords: | cosmic microwave background cosmology: theory dark matter gravitational lensing large-scale structure of Universe |
|
|
