New early dark energy (NEDE) is a component of vacuum energy at the electron volt scale,
which decays in a first-order phase transition shortly before recombination [F. Niedermann …

We investigate the cosmological perturbations in f (T) gravity. Examining the pure
gravitational perturbations in the scalar sector using a diagonal vierbein, we extract the …

We investigate f (T) cosmology in both the background, as well as in the perturbation level,
and we present the general formalism for reconstructing the equivalent one-parameter …

Abstract Homogeneous and anisotropic Kantowski–Sachs model sourced by a stiff fluid and
cosmological constant has been explored for different possible scenarios of the universe …

We use observational data from Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations
(BAO), and Cosmic Microwave Background (CMB), along with requirements of Big Bang …

False vacuum decay in quantum mechanical first order phase transitions is a phenomenon
with wide implications in cosmology and presents interesting theoretical challenges. In the …

In this paper we investigate a time-varying neutrino mass model, motivated by the mild
tension between cosmic microwave background (CMB) measurements of the matter …

We show how recent data from observations of the cosmic microwave background may
suggest the presence of additional radiation density which appeared after big bang …

Models that lead to a cosmological stiff fluid component, with a density ρ S that scales as a-
6, where a is the scale factor, have been proposed recently in a variety of contexts. We …

We derive slow-roll conditions for thawing k-essence with a separable Lagrangian p (X, ϕ)=
F (X) V (ϕ). We examine the evolution of the equation of state parameter, w, as a function of …