Quasar clustering redshift distortion constraints, on dark energy

Redshift distortions, both geometrical and kinematical, of quasar clustering are simulated, for the Two-Degree Field QSO Redshift Survey (2QZ), showing that they are very effective to constrain the cosmological density and equation of state parameters, Omega(m0), Omega(x0) and w. Particularly, it emerges that, for the cosmological constant case, the test is especially sensitive to the difference Omega(m0) - Omega(Lambda0), whereas, for the spatially flat case, it is quite competitive with future supernova and galaxy count tests, besides being complimentary to them.