Is Cosmic Speed-Up Due to New Gravitational Physics?

@article{Carroll2004IsCS,
  title={Is Cosmic Speed-Up Due to New Gravitational Physics?},
  author={S. Carroll and Vikram Duvvuri and Mark Trodden and Michael S. Turner},
  journal={Physical Review D},
  year={2004},
  volume={70},
  pages={043528}
}
We show that cosmic acceleration can arise due to very tiny corrections to the usual gravitational action of general relativity, of the form ${R}^{\ensuremath{-}n}$ with $ng0.$ This model eliminates the need for a nonzero cosmological constant or any other form of dark energy, attributing a purely gravitational origin to the acceleration of the universe. 

Figures from this paper

Dark Energy and Cosmic Speed-Up from Consistent Modified Gravity
We review some modified gravity models which describe the gravitational dark energy and the possibility of cosmic speed-up. The new consistent version of such theory which contains inverse and HD
Cosmic vector for dark energy
In this work we show that the presence of a vector field on cosmological scales could explain the present phase of accelerated expansion of the Universe. The proposed theory contains no dimensional
The Effective Action Formalism for Cosmological Perturbations
The standard model of cosmology uses General Relativity (GR) to describe gravitational interactions, an homogeneous/isotropic FRW metric to describe the geometry and matter content of cold dark
Approaches to Understanding Cosmic Acceleration
Theoretical approaches to explaining the observed acceleration of the universe are reviewed. We briefly discuss the evidence for cosmic acceleration, and the implications for standard general
The gravitational rainbow beyond Einstein gravity
The recent direct detection of gravitational waves have been successfully used to examine the basic properties of the gravitational degrees of freedom. They set an upper bound on their mass and
Gravitational coupling and the cosmological constant
  • Y. Bisabr
  • Physics
    International Journal of Modern Physics D
  • 2018
We deal with a dynamical mechanism in which a large cosmological constant, as suggested by inflationary scenarios, decays due to expansion of the universe. This mechanism has its origin in the
Dark torsion as the cosmic speed-up
It is shown that the recently detected acceleration of the Uuniverse can be understood by considering a modification of the teleparallel equivalent of general relativity, with no need of dark energy.
Can Neutrino Viscosity Drive the Late Time Cosmic Acceleration?
In this paper it has been shown that the neutrino bulk viscous stresses can give rise to the late time acceleration of the universe. It is found that a number of spatially flat FRW models with a
The Power Spectrum Of Gravitational Waves In Anisotropic Universe
In this paper the Gravitational waves (GW) due to models of gravitational action (that is liner $R$ and quadratic $R^{2}$ gravity) in a perturbed anisotropic metric are considered. Also the power
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 32 REFERENCES
Dynamical solution to the problem of a small cosmological constant and late-time cosmic acceleration
TLDR
In the theories considered, the dynamics causes the scalar field to lock automatically into a negative pressure state at the onset of matter domination such that the present epoch is the earliest possible time consistent with nucleosynthesis restrictions when it can start to dominate.
The Cosmological Constant
  • S. Carroll
  • Physics, Medicine
    Living reviews in relativity
  • 2001
TLDR
A pedagogical overview of cosmology in the presence of a cosmological constant, observational constraints on its magnitude, and the physics of a small (and potentially nonzero) vacuum energy are presented.
Cosmological imprint of an energy component with general equation of state
We examine the possibility that a significant component of the energy density of the Universe has an equation of state different from that of matter, radiation, or cosmological constant ({Lambda} ).
Accelerated universe from gravity leaking to extra dimensions
We discuss the idea that the accelerated universe could be the result of gravitational leakage into extra dimensions over Hubble distances rather than the consequence of a nonzero cosmological
Everpresent Lambda
A variety of observations indicate that the universe is dominated by dark energy with negative pressure, one possibility for which is a cosmological constant. If the dark energy is a cosmological
The Cosmological Constant and Dark Energy
Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda: nowadays the concept is termed dark energy or
...
1
2
3
4
...