High-z X-ray AGN Clustering and Cosmological Implications
  I review recent results of the high-redshift X-ray selected AGN clustering, based on the XMM/2dF survey. Using the luminosity-dependent density evolution luminosity function we find that the spatial clustering lengths, derived using Limber's inversion equation, are ~16 and ~19 h-1 Mpc respectively (for the comoving clustering evolution model) while the median redshifts of the soft and hard X-ray sources are z~ 1.2 and 0.75, respectively. Within the framework of flat cosmological models we find that these results support a model with Omega_m=0.26, \sigma_8=0.75, w=-0.9 (in excellent agreement with the 3 year WMAP results). We also find the present day bias of X-ray AGNs to be b_o=2. 
Manolis Plionis