相关论文: Late time acceleration in Palatini gravity

In this paper we examine the cosmological consequences of fourth order Galileon gravity. We carry out detailed investigations of the underlying dynamics and demonstrate the stability of one de Sitter phase. The stable de Sitter phase…

We investigate the linearly and quadratically coupled cubic Galileon models that include linear potentials. These models may explain the late-time acceleration. In these cases, we need two equations of state parameter named the native and…

We review recently offered notions of quasi-static evolution of the axial self-gravitating structures at large-scales and the criteria to characterize the corresponding evolutionary aspects under the influence of strong curvature regimes.…

We demonstrate how to describe in an unified way early and late-time acceleration in the context of mimetic $F(R)$ gravity. As we show, an exponential $F(R)$ gravity model has appealing features, with regard to unification, and we perform…

It has been proposed recently the existence of a non-minimal coupling between a canonical scalar field (quintessence) and gravity in the framework of teleparallel gravity, motivated by similar constructions in the context of General…

Once quantum corrections are taken into account, the strong coupling limit of the $\xi$-attractor models (in metric gravity) might depart from the usual Starobinsky solution and move into linear inflation. Furthermore, it is well known that…

High-precision observational data have confirmed with startling evidence that the Universe is currently undergoing a phase of accelerated expansion. This phase, one of the most important and challenging current problems in cosmology,…

We examine quintessence models for dark energy in which the scalar field, $\phi$, evolves near the vicinity of a local maximum or minimum in the potential $V(\phi)$, so that $V(\phi)$ be approximated by a quadratic function of $\phi$ with…

We study Higgs inflation in the Palatini formulation with the renormalisation group improved potential in the case when loop corrections generate a feature similar to an inflection point. Assuming that there is a threshold correction for…

We consider models of a scalar field coupled to quadratic $R\!+\!R^2$ gravity in the framework of the Palatini formulation. The resulting Einstein-frame generalized $k$-inflation effective theory is analyzed assuming that the constant-roll…

We examine in the context of general relativity the dynamics of a spatially flat Robertson-Walker universe filled with a classical minimally coupled scalar field \phi of exponential potential ~ e^{-\mu\phi} plus pressureless baryonic…

We investigate inflation in modified gravity framework by introducing a direct coupling term between a scalar field $\phi$ and the trace of the energy momentum tensor $T$ as $f(\phi,T) = 2 \phi( \kappa^{1/2} \alpha T + \kappa^{5/2} \beta…

We study new FRW type cosmological models of modified gravity treated on the background of Palatini approach. These models are generalization of Einstein gravity by the presence of a scalar field non-minimally coupled to the curvature. The…

In the context of modified gravity, we point out how the Palatini version of these theories is singled out as a very special case corresponding to the unique fixed point of a transformation involving a special conformal rescaling of the…

This thesis presents research exploring aspects of inflation and cosmology in the context of inflation models in which an inflaton is non-minimally coupled to the Ricci scalar, or is considered in conjunction with a term quadratic in the…

In this paper, we investigate the freezing quintessence scenario in late-time cosmic expansion using a non-linear $f(R, L_m)$ gravity model, $f(R,L_m)=\frac{R}{2}+L_m^\alpha$, where $\alpha$ is a free parameter. We consider a solution for…

In this work, we introduce two models of the hybrid metric-Palatini theory of gravitation. We explore their background evolution, showing explicitly that one recovers standard General Relativity with an effective Cosmological Constant at…

We study modified theories of gravity of the f(R) type in Palatini formalism. We first consider the stability of atoms when the Palatini gravitational interaction is taken into account in the derivation of the non-relativistic Schrodinger…

We construct an analytic f(R) gravity model that unifies early-time inflation with late-time cosmic acceleration within a single covariant framework. At high curvature, the model reproduces a Starobinsky-like inflationary plateau, while at…

We revisit the growth of curvature perturbations in non-minimal curvaton scenario with a non-trivial field metric $\lambda(\phi)$ where $\phi$ is an inflaton field, and incorporate the effect from the non-uniform onset of curvaton's…