SPHERICALLY SYMMETRICAL COSMOLOGICAL PERTURBATION IN A UNIVERSE WITH BACKGROUND FIELD

In a previous paper the equations of small cosmological perturbations of a theory of gravitation in flat space-time are derived. They are ap plied to a homogeneous, isotropic, nonsingular cosmological model with radiation, matter and background field. At the beginning of the unive rse small spherically symmetric inhomogeneities on almost all scales c an arise by instability. Later on the density contrast of dust grows e xponentially during a short time epoch. The solution during this time period is given analytically.