Primordial black holes formed in the early Universe via gravitational collapse of over-dense
regions may contribute a significant amount to the present dark matter relic density. Inflation …

Some models within the framework of Gauss–Bonnet gravities are considered in the
presence of a non-minimally coupled scalar field. By imposing a particular constraint on the …

In the era of precision cosmology, different observational data has led to precise
measurements of the Hubble constant that differ significantly, what has been called the …

In the gravitational effective theories including higher curvature terms, cosmological
solutions can have nontrivial de Sitter fixed points. We study phenomenological implications …

Inflationary models with a scalar field nonminimally coupled both with the Ricci scalar and
with the Gauss–Bonnet term are studied. We propose the way of generalization of …

De Sitter solutions play an important role in cosmology because the knowledge of unstable
de Sitter solutions can be useful to describe inflation, whereas stable de Sitter solutions are …

Ostrogradsky instability generally appears in nondegenerate higher-order derivative
theories and this issue can be resolved by removing any existing degeneracy present in …

Higher-curvature corrections to the effective gravitational action may leave signatures in the
spectrum of primordial tensor perturbations if the inflationary energy scale is sufficiently high …

We investigate cosmological perturbations of f (G) gravity in the presence of a scalar field.
Using the 1+ 3 covariant formalism, we present the energy overdensity perturbation …

In this work, we present the late-time behaviour of the universe in the context of Einstein–
Gauss–Bonnet gravitational theory. The theory involves a scalar field, which represents low …