Constraining the CDM spectrum normalization in flat dark energy cosmologies

Abstract

We study the relation between the rms mass fluctuations on 8$h^{-1}$Mpc scales and ${\Omega }_{\mathrm{m}}$ using the recent clustering results of XMM-{\it Newton} soft (0.5-2 keV) X-ray sources, which have a median redshift of $z\sim 1.2$. The relation can be represented in the form ${\sigma }_8=0.34(\pm 0.01){\Omega }_{\mathrm{m}}^{-\gamma }$ where $\gamma \equiv \gamma ({\Omega }_{\mathrm{m}},w)$ and it is valid for all $w<-1/3$ models. By combining the X-ray clustering and SNIa data we find that the model which best reproduces the observational data is that with: ${\Omega }_{\mathrm{m}}\simeq 0.26$, $w\simeq -0.90$ and ${\sigma }_8\simeq 0.73$, which is in excellent agreement with the recent 3-year Wilkinson Microwave Anisotropy Probe results.

4 pages, 2 figures, ApJ Letters in press

Cited by in corpus (2)

• Large scale structure in the HI Parkes All-Sky Survey: Filling the Voids with HI galaxies?
• Constraining Dark Energy From Splitting Angle Statistic of Strong Gravitational Lenses