Cosmological Models

For the DEUS Full Universe Run we have selected 3 cosmological models calibrated on CMB data. These consists of a concordance ΛCDM model best fitting WMAP7-yr and two non-standard dark energy models which are statistically consistent with WMAP7-yr and Supernova Ia UNION data.

The model parameters for the non-standard dark energy models are chosen such as to be in agreement with both CMB and SN Ia data (<2σ), with values of the equation of state and matter density which are chosen along the line of degeneracy of SN Ia luminosity distance measurements. This is to test whether dark energy imprint on the non-linear structure formation can break the cosmic distance degeneracy. On the other hand the normalization of the linear matter power spectrum on the 8 Mpc/h scale is chosen along the line of degeneracy of CMB data such as to be in agreement with the WMAP7-yr data normalization spectrum. The dark energy model with w=-0.87 is the quintessence RPCDM model also considered in the DEUSS runs, while the model with w=-1.2 is a phantom fluid dark energy model.

1 and 2σ Likelihood contours in the w-Ωm (top panel) and w-σ8 (bottom panel) planes respectively. The solid lines corresponds to marginalized limits from WMAP7-yr data, while the red-yellow contours in the top panel are from the combined analysis with the SN Ia from the UNION dataset. The symbols corresponds to RPCDM (+), ΛCDM-W7 (x) and wCDM (o).

With this choice of cosmological parameters the two non-standard dark energy models exhibit a linear growth of the density perturbations that is specular relative to that of the concordance model.

Linear growth factor for wCDM (dot line) and RPCDM (long dash line) relative to the concordance LCDM model.