Simple cosmological model with inflation and late times acceleration

Abstract

In the framework of polynomial Palatini cosmology, we investigate a simple cosmological homogeneous and isotropic model with matter in the Einstein frame. We show that in this model during cosmic evolution, it appears the early inflation and the accelerating phase of the expansion for the late times. In this frame we obtain the Friedmann equation with matter and dark energy in the form of a scalar field with the potential whose form is determined in a covariant way by the Ricci scalar of the FRW metric. The energy density of matter and dark energy are also parametrized through the Ricci scalar. The early inflation is obtained only for an infinitesimally small fraction of energy density of matter. Between the matter and dark energy, there exists interaction because the dark energy is decaying. For characterization of inflation we calculate the slow roll parameters and the constant roll parameter in terms of the Ricci scalar. We have found a characteristic behaviour of the time dependence of density of dark energy on the cosmic time following the logistic-like curve which interpolates two almost constant value phases. From the required numbers of $N$-folds we have found a bound on model parameter.

arXiv comment8 pages, 10 figures

References in corpus (34)

• f(R) Theories Of Gravity
• f(R) theories
• Extended Theories of Gravity
• A Joint Analysis of BICEP2/Keck Array and Planck Data
• Cosmological viability of f(R)-gravity as an ideal fluid and its compatibility with a matter dominated phase
• Palatini Approach to Modified Gravity: f(R) Theories and Beyond
• On Physical Equivalence between Nonlinear Gravity Theories
• Inflationary paradigm in trouble after Planck2013
• Curing singularities in cosmological evolution of F(R) gravity
• Dark Energy: the equation of state description versus scalar-tensor or modified gravity
• Matter instability in modified gravity
• Accelerated Cosmological Models in Ricci squared Gravity
• Early Dark Energy Cosmologies
• On the Starobinsky Model of Inflation from Supergravity
• Comments on the Starobinsky Model of Inflation and its Descendants
• Aspects of Quadratic Gravity
• A polynomial f(R) inflation model
• Physical non-equivalence of the Jordan and Einstein frames
• How early is early dark energy?
• $f(R)$ constant-roll inflation
• Conformal aspects of Palatini approach in Extended Theories of Gravity
• Constant-roll inflation: confrontation with recent observational data
• Higher Order Corrections in Minimal Supergravity Models of Inflation
• ${\mathcal{R}}^2$ inflation from scale invariant supergravity and anomaly free superstrings with fluxes
• The Parameterised Post-Newtonian Limit of Fourth-Order Theories of Gravity
• Towards Axionic Starobinsky-like Inflation in String Theory
• Connecting early and late universe by $f(R)$ gravity
• Phenomenological Aspects of No-Scale Inflation Models
• From Dark Energy and Dark Matter to Dark Metric
• Starobinsky cosmological model in Palatini formalism
• Relic gravitational waves from Quintessential Inflation
• Starobinsky-Type Inflation from ${\alpha }^{\prime }$-Corrections
• Emergence of dynamical dark energy from polynomial $f(R)$ theory in Palatini formalism
• Constraints on single-field inflation with WMAP, SPT and ACT data -- A last-minute stand before Planck

Cited by in corpus (4)

• Cosmology with a new f(R) gravity model in Palatini formalism
• Extended Cosmology in Palatini f(R)-theories
• Space-time second-quantization effects and the quantum origin of cosmological constant in covariant quantum gravity
• Polynomial $f(R)$ Palatini cosmology -- dynamical system approach