ABSTRACT
Redshift surveys have become a powerful tool for probing both the dynamics of galaxy motions on large scales and the nature of the background cosmological model in which the galaxies are embedded. This chapter describes some of the techniques which have been developed to reconstruct the galaxy density and velocity fields on large scales, and to use these reconstructed fields to place constraints on the parameters of the underlying cosmological model. It sets out to answer three basic questions: What are galaxy redshift surveys? Why are they (cosmologically) interesting? and How do we extract useful cosmological information from them? The chapter reviews the essential theoretical elements which relate the parameters of cosmological models to the formation of structure in the Universe under the influence of gravity. The gravitational instability paradigm is the standard theoretical framework which describes the growth of structure on cosmological scales.
