BREAKING THE σ8-Ωm DEGENERACY USING THE CLUSTERING OF HIGH-z X-RAY ACTIVE GALACTIC NUCLEI

The clustering of X-ray selected active galactic nuclei (AGNs) appears to be a valuable tool for extracting cosmological information. Using the recent high-precision angular clustering results of similar to 30,000 XMM-Newton soft (0.5-2 keV) X-ray sources, which have a median redshift of z similar to 1, and assuming a flat geometry, a constant in comoving coordinates AGN clustering evolution, and the AGN bias evolution model of Basilakos et al., we manage to break the sigma(8)-Omega(m) degeneracy. The resulting cosmological constraints are Omega(m) = 0.27(-0.05)(+0.03), w = -0.90(-0.16)(+0.10), and sigma(8) = 0.74(-0.12)(+0.14), while the dark matter host halo mass, in which the X-ray selected AGNs are presumed to reside, is M = 2.50(-1.50)(+0.50) x 10(13) h(-1) M-circle dot. For the constant Lambda model (w = -1) we find Omega(m) = 0.24 +/- 0.06 and sigma(8) = 0.83(-0.16)(+0.11), in good agreement with recent studies based on cluster abundances, weak lensing, and the cosmic microwave background, but in disagreement with the recent bulk flow analysis.