Adding the terms quadratic in the curvature to the Einstein-Hilbert action renders gravity
renormalizable. This property is preserved in the presence of the most general …

The dawn of the twenty-first century came with very positive prospects for gravity, cosmology,
and astrophysics. Technological progress made it possible for cosmology to enter to its …

We review (and extend) the analysis of general theories of all interactions (gravity included)
where the mass scales are due to dimensional transmutation. Quantum consistency requires …

Studies of dark energy at advanced gravitational-wave (GW) interferometers normally focus
on the dark energy equation of state w DE (z). However, modified gravity theories that …

The cosmological constant (CC) term in Einstein's equations, Λ, was first associated to the
idea of vacuum energy density. Notwithstanding, it is well-known that there is a huge, in fact …

In modified gravity the propagation of gravitational waves (GWs) is in general different from
that in general relativity. As a result, the luminosity distance for GWs can differ from that for …

Even if the fundamental action of gravity is local, the corresponding quantum effective action,
that includes the effect of quantum fluctuations, is a nonlocal object. These nonlocalities are …

Despite the many outstanding cosmological observations leading to a strong evidence for a
non-vanishing cosmological constant (CC) term Λ in the gravitational field equations, the …

We use the functional renormalization group equation for quantum gravity to construct a
nonperturbative flow equation for modified gravity theories of the form S=∫ ddxgf (R). Based …

We investigate the properties of the FLRW flat cosmological models in which the vacuum
energy density evolves with time, Λ (t). Using different versions of the Λ (t) model, namely …