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 (
), clustering in the Universe in the range
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
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].