We study a model including a real scalar field ϕ ϕ non-minimally coupled to F (R) F (R)
gravity, which is conformally equivalent to an Einstein–Hilbert theory, involving two real …

Thanks to the Planck Collaboration, we know the value of the scalar spectral index of
primordial fluctuations with unprecedented precision. In addition, the joint analysis of the …

We derive the flow equation for the gravitational effective average action in an f (R)
truncation on hyperbolic spacetimes using the exponential parametrization of the metric. In …

We consider an inflationary model motivated by quantum effects of gravitational and matter
fields near the Planck scale. Our Lagrangian is a resummed version of the effective …

We consider R p inflation with p≈ 2, allowing small deviation from R 2 inflation. Using the
inflaton potential in the Einstein frame, we construct a consistency relation between the …

The BICEP2 collaboration has recently released data showing that the scalar-to-tensor ratio
r is much larger than expected. The immediate consequence, in the context of f (R) gravity, is …

We study slow-roll inflation as a common feature in Metric-affine Theories of Gravity. In
particular, we take into account extended metric, teleparallel and symmetric-teleparallel …

The standard Starobinsky inflation has been extended to the R+ α R n-β R 2-n model to
obtain a stable minimum of the Einstein frame scalar potential of the auxiliary field. As a …

We construct the covariant effective field theory of gravity as an expansion in inverse powers
of the Planck mass, identifying the leading and next-to-leading quantum corrections. We …

Inflationary models derived from f (R) gravity, where the scalaron rolls down with a constant
rate from the top to the minimum of the effective potential, are considered. Specifically, we …