COSMOLOGICAL PERTURBATIONS IN PRESENCE OF SCALAR FIELDS

We investigate the role of the scalar field assuming its presence at late stages of the Universe evolution together with dust presented by a system of an arbitrary number of gravitating masses (galaxies, groups of galaxies and clusters of galaxies) and the cosmological constant in the framework of the theory of scalar cosmological perturbations. In particular,we discuss the case of the homogeneous scalar field and its possible influence on the gravitational potentials representing metric perturbations. We also focus attention on the interconnection between the astrophysical problem and the cosmological one in thescalar field presence.We investigate the role of the scalar field assuming its presence at late stages of the Universe evolution together with dust presented by a system of an arbitrary number of gravitating masses (galaxies, groups of galaxies and clusters of galaxies) and the cosmological constant in the framework of the theory of scalar cosmological perturbations. In particular,we discuss the case of the homogeneous scalar field and its possible influence on the gravitational potentials representing metric perturbations. We also focus attention on the interconnection between the astrophysical problem and the cosmological one in thescalar field presence