Observational constraints on a phenomenological $$f\left( R,\partial R\right) $$fR,∂R-model

@article{Cuzinatto2013ObservationalCO,
  title={Observational constraints on a phenomenological \$\$f\left( R,\partial R\right) \$\$fR,∂R-model},
  author={Rodrigo Rocha Cuzinatto and C.A.M. de Melo and L{\'e}o G. Medeiros and P. J. Pompeia},
  journal={General Relativity and Gravitation},
  year={2013},
  volume={47},
  pages={1-22}
}
This paper analyses the cosmological consequences of a modified theory of gravity whose action integral is built from a linear combination of the Ricci scalar $$R$$R and a quadratic term in the covariant derivative of $$R$$R. The resulting Friedmann equations are of the fifth-order in the Hubble function. These equations are solved numerically for a flat space section geometry and pressureless matter. The cosmological parameters of the higher-order model are fit using SN Ia data and X-ray gas… 
13 Citations

Gravitational waves in higher-order R2 gravity

We perform a comprehensive study of gravitational waves in the context of the higher-order quadratic scalar curvature gravity, which encompasses the ordinary Einstein-Hilbert term in the action plus

Scalar-multitensor approach to teleparallel modified theories of gravity

The analysis of teleparallel f(T,∇μ1T,…,∇μn⋯∇μ1T) gravity in the Jordan and Einstein frames is presented. The equivalence between f(T,∇μ1T,…,∇μn⋯∇μ1T) gravity and a scalar-multitensor theory is

Novel higher-curvature variations of R2 inflation

We put forward novel extensions of Starobinsky inflation, involving a class of 'geometric' higher-curvature corrections that yield second-order Friedmann-Lema\^itre equations and second-order-in-time

Black holes and wormholes in f(R) gravity with a kinetic curvature scalar

We study the chiral self-gravitating model (CSGM) of a special type in the spherically symmetric static spacetime in Einstein frame. Such CSGM is derived, by virtue of Weyl conformal transformation,

Chiral Cosmological Model of f(R) Gravity with a Kinetic Curvature Scalar

We consider modified f(R) gravity with a kinetic curvature scalar, which can be reduced to a chiral cosmological model of special kind. A detailed derivation is presented for the action of a chiral

f(R,∇μ1R,…,∇μ1…∇μnR) theories of gravity in Einstein frame: A higher order modified Starobinsky inflation model in the Palatini approach

In Cuzinatto et al. [Phys. Rev. D 93, 124034 (2016)], it has been demonstrated that theories of gravity in which the Lagrangian includes terms depending on the scalar curvature $R$ and its

Cosmology of f(R,❑R) gravity

Using dynamical system analysis, we explore the cosmology of theories of order up to eighth order of the form $f(R,❑R)$. The phase space of these cosmologies reveals that higher-order terms can have

A Newton method for harmonic mappings in the plane

We present an iterative root finding method for harmonic mappings in the complex plane, which is a generalization of Newton's method for analytic functions. The complex formulation of the method

On higher derivative corrections to the R+R2 inflationary model

The R+R2 model is successful in describing inflation, as it provides an excellent fit to the full set of available observational data. On the other hand, the same model is the simplest extension of

Geometrothermodynamics of Van der Waals black hole

We study the geometrothermodynamics of a special asymptotically AdS black hole, i.e. Van der Waals $$\left( VdW\right) $$VdW black hole, in the extended phase space where the negative cosmological

References

SHOWING 1-10 OF 80 REFERENCES

Improved constraints on dark energy from Chandra X-ray observations of the largest relaxed galaxy clusters

We present constraints on the mean matter density, � m, dark energy density, � DE, and the dark energy equation of state parameter, w, using Chandra measurements of the X-ray gas mass fraction (fgas

REALISTIC CYCLIC MAGNETIC UNIVERSE

This work presents a complete cyclic cosmological scenario based on nonlinear magnetic field. It is constructed from a model composed of five fluids, namely baryonic matter, dark matter, radiation,

OBSERVATIONAL EVIDENCE FROM SUPERNOVAE FOR AN ACCELERATING UNIVERSE AND A COSMOLOGICAL CONSTANT

We present spectral and photometric observations of 10 Type Ia supernovae (SNe Ia) in the redshift range 0.16 " z " 0.62. The luminosity distances of these objects are determined by methods that

Overview of products and scientific results

The European Space Agency's Planck satellite, dedicated to studying the early Universe and its subsequent evolution, was launched 14~May 2009 and scanned the microwave and submillimetre sky

Sixth-order gravity and conformal transformations

The author proves a general conformal equivalence between pairs of Lagrangians (L(R); L(R)) and applies it to the pair (Rm; Rm) with m=(3m-4)/(2m-3).

The Cosmological Constant Problem

Astronomical observations indicate that the cosmological constant is many orders of magnitude smaller than estimated in modern theories of elementary particles. After a brief review of the history of

Backreaction: directions of progress

Homogeneous and isotropic cosmological models with ordinary matter and gravity predict slower expansion and shorter distances than observed. It is possible that this failure is due the known
...