Dustlike stages in the early Universe and restrictions on the spectrum of primordial black holes

Early stages of the Universe evolution are investigated. The account for possible early dustlike stages in the Universe is shown to result in the softening of the limits on the fraction of the matter that went into primordial black holes (PBH). Restrictions on the parameters of grand unified theories are given with an account for such softening. The conclusion is made that the inhomogeneity of the early Universe on small scales may be compatible with modern observational limits on the PBH spectrum