Primordial Black Holes Formation in Inflationary F (R) Models with Scalar Fields

We construct F (R) gravity models with scalar fields to describe cosmological inflation and formation of primordial black holes (PBHs). By adding the induced gravity term and the fourth-order polynomial potential for the scalar field to the known F (R) gravity model, and using a conformal transformation of the metric, we obtain a two-field chiral cosmological model. For some values of the model parameters, we get that the inflationary parameters of this model are in good agreement with the observations of the cosmic microwave background radiation obtained by the Atacama Cosmology Telescope. The estimation of PBH masses suggests that PBHs could be dark matter candidates.