WMAP constraints on low redshift evolution of dark energy

Abstract

The conceptual difficulties associated with a cosmological constant have led to the investigation of alternative models in which the equation of state parameter, $w=p/\rho$, of the dark energy evolves with time. We show that combining the supernova type Ia observations {\it with the constraints from WMAP observations} restricts large variation of $\rho(z)$ at low redshifts. The combination of these two observational constraints is stronger than either one. The results are completely consistent with the cosmological constant as the source of dark energy.Comment: Final version to appear in MNRAS (Letters); discussion enlarged and clarifications and references added; 6 pages; 3 figure

Dark Energy

“…Due to the lack of a compelling fundamental theory to explain the dark energy, another route, the model-independent dark energy reconstructions, have drawn more and more attentions [566,709,710,711,712,713,714,715,716,717].…”

Linear and non-linear perturbations in dark energy models

“…Currently, there is no strong observational evidence either for departures from w = −1 or for a time evolution of the dark energy EoS. However, since such results would be of great impact on cosmology, a number of studies on dark energy parameterisations have been discussed in the literature (see, e.g., [11][12][13][14][15][16] and references therein).…”

Cosmology with decaying tachyon matter

“…The fact that the model fits the data quite well is appealing but to improve on it we must add further necessary features which are required for a realistic cosmological model. Finally, it might be worthwhile looking at cosmological perturbations in this model and try to use WMAP data to set more stringent bounds on the parameters [17,18].…”