Relativistic Effects Observable in Clustering at High Redshifts

5 Relativistic Effects Observable in Clustering at High Redshifts

Redshift surveys of galaxies definitely serve as the central database for observational cosmology. In addition to the existing shallower surveys ( $z < 0.2$ ), clustering in the Universe in the range $z = 1– 3$ has been partially revealed by, for instance, the Lyman-break galaxies and X-ray selected AGNs. In particular, the 2dF and SDSS QSO redshift surveys promise to extend the observable scale of the Universe by an order of magnitude, up to a few Gpc. A proper interpretation of such redshift surveys in terms of the clustering evolution, however, requires an understanding of many cosmological effects which can be neglected for $z ≪ 1$ and thus have not been considered seriously so far. These cosmological contaminations include linear redshift-space (velocity) distortion, nonlinear redshift-space (velocity) distortion, cosmological redshift-space (geometrical) distortion, and the cosmological light-cone effect.

We describe a theoretical formalism to incorporate those effects, in particular the cosmological redshift-distortion and light-cone effects, and present several specific predictions in CDM models. The details of the material presented in this section may be found in [83 , 101 , 100 , 46 , 28 , 29 ].

5.1 Cosmological light-cone effect on the two-point correlation functions
5.2 Evaluating two-point correlation functions from N-body simulation data
5.3 Cosmological redshift-space distortion
5.4 Two-point clustering statistics on a light-cone in cosmological redshift space