19 Citations
Density perturbations in f(R) gravity theories in metric and Palatini formalisms
- Physics
- 2008
We make a detailed study of matter density perturbations in both metric and Palatini formalisms. Considering general theories whose Lagrangian density is a general function, $f(R)$, of the Ricci…
A simple F ( R , φ) deformation of Starobinsky inflationary model
- Physics, Mathematics
- 2020
We study a model including a real scalar field φ non-minimally coupled to F ( R ) gravity, which is conformally equivalent to an Einstein–Hilbert theory, involving two…
Beyond the concordance cosmology
- Physics
- 2013
For almost a hundred years now, Einstein’s General Relativity theory has played a pivotal role in our understanding of the Universe. The recent realization of the accelerated cosmic expansion,…
Inflation in f(R,h) theory formulated in the Palatini formalism
- Physics
- 2020
A new model for inflation using modified gravity in the Palatini formalism is constructed. Here non-minimal coupling of scalar field h with the curvature R as a general function f(R,h) is considered.…
f(R) Theories
- PhysicsLiving reviews in relativity
- 2010
Various applications of f(R) theories to cosmology and gravity — such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds are reviewed.
Inflation and Reheating in f(R,h) theory formulated in the Palatini formalism
- MathematicsJournal of Cosmology and Astroparticle Physics
- 2020
A new model for inflation using modified gravity in the Palatini formalism is constructed. Here non-minimal coupling of scalar field h with the curvature R as a general function f(R,h) is considered.…
Black-hole solutions in F(R) gravity with conformal anomaly
- Physics
- 2011
In this paper, we consider F(R)=R+f(R) theory instead of Einstein gravity with conformal anomaly and look for its analytical solutions. Depending on the free parameters, one may obtain both uncharged…
Constant-Roll Inflation in modified $f(R,\phi)$ gravity model using Palatini Formalism
- Physics
- 2022
In this work, we study a constant-roll inflationary model in the Palatini formalism using modified gravity. Here our action consists a non-minimal coupling of a scalar field φ with Ricci scalar R in a…
Inflation with $$f(R,\phi )$$f(R,ϕ) in Jordan frame
- PhysicsGeneral Relativity and Gravitation
- 2018
We consider an f(R) action that is non-minimally coupled to a massive scalar field. The model closely resembles scalar–tensor theory and by conformal transformation can be transformed to Einstein…
Inflation with f ( R , (cid:2) ) in Jordan frame
- Physics
- 2018
We consider an f ( R ) action that is non-minimally coupled to a massive scalar field. The model closely resembles scalar–tensor theory and by conformal transformation can be transformed to Einstein…
References
SHOWING 1-10 OF 40 REFERENCES
One-loop f(R) gravity in de Sitter universe
- Physics
- 2005
Motivated by the dark energy issue, the one-loop quantization approach for a family of relativistic cosmological theories is discussed in some detail. Specifically, general f(R) gravity at the…
INTRODUCTION TO MODIFIED GRAVITY AND GRAVITATIONAL ALTERNATIVE FOR DARK ENERGY
- Physics
- 2006
We review various modified gravities considered as gravitational alternative for dark energy. Specifically, we consider the versions of f(R), f(G) or f(R, G) gravity, model with non-linear…
Avoiding dark energy with 1/r modifications of gravity
- Physics
- 2006
Scalar quintessence seems epicyclic because one can choose the potential to reproduce any cosmology (I review the construction) and because the properties of this scalar seem to raise more questions…
AdS and stabilized extra dimensions in multi-dimensional gravitational models with nonlinear scalar curvature terms R−1 and R4
- Mathematics
- 2004
We study multi-dimensional gravitational models with scalar curvature nonlinearities of types R−1 and R4. It is assumed that the corresponding higher dimensional spacetime manifolds undergo a…
MODIFIED F (R) GRAVITY CONSISTENT WITH REALISTIC COSMOLOGY: FROM A MATTER DOMINATED EPOCH TO A DARK ENERGY UNIVERSE
- Physics
- 2006
We develop the general scheme for modified f(R) gravity reconstruction from any realistic Friedmann-Robertson-Walker (FRW) cosmology. We formulate several versions of modified gravity compatible with…
Dark energy in modified Gauss-Bonnet gravity: Late-time acceleration and the hierarchy problem
- Physics
- 2006
Dark energy cosmology is considered in a modified Gauss-Bonnet (GB) model of gravity where an arbitrary function of the GB invariant, f(G), is added to the general relativity action. We show that a…
The accelerating Universe and a limiting curvature proposal
- Physics
- 2006
We consider the hypothesis of a limiting minimal curvature in gravity as a way to construct a class of theories exhibiting late-time cosmic acceleration. Guided by the minimal curvature conjecture we…