# Ghosts in the self-accelerating universe

@article{Koyama2007GhostsIT, title={Ghosts in the self-accelerating universe}, author={Kazuya Koyama}, journal={Classical and Quantum Gravity}, year={2007}, volume={24} }

The self-accelerating universe realizes the accelerated expansion of the universe at late times by large-distance modification of general relativity (GR) without a cosmological constant. The Dvali–Gabadadze–Porrati (DGP) braneworld model provides an explicit example of the self-accelerating universe. Recently, the DGP model became very popular for studying the observational consequences of the modified gravity models as an alternative to dark energy models in GR. However, it has been shown that…

## 82 Citations

Stability of self-accelerating solutions in modified gravity models

- Physics
- 2010

The observed accelerated expansion of the universe is one of the big issues of modern cosmology. One possible way of understanding it is by modifying General Relativity so that gravity is weaker at…

Cosmological and thermodynamics consequences of viscous modified theories of gravity

- Physics
- 2019

The illustration of cosmic acceleration is being presented in the framework of DGP braneworld and dynamical Chern–Simons modified gravity in the presence of casual Israel–Stewart formalism. In this…

Self-accelerating the normal DGP branch

- Physics
- 2009

We propose a generalised induced gravity brane-world model where the brane action contains an arbitrary f(R) term, R being the scalar curvature of the brane. We show that the effect of the f(R) term…

Ghosts in the self-accelerating DGP branch with Gauss–Bonnet effect

- Physics
- 2014

The Dvali–Gabadadze–Porrati brane-world model provides a possible approach to address the late-time cosmic acceleration. However, it has subsequently been pointed out that a ghost instability will…

Cosmological tests of modified gravity.

- Physics, MedicineReports on progress in physics. Physical Society
- 2016

An overview of recent developments in modified gravity theories including f(R) gravity, braneworld gravity, Horndeski theory and massive/bigravity theory is given and how to test modifications of gravity on cosmological scales is discussed.

Self-interacting scalar field trapped in a DGP brane: The dynamical systems perspective

- Physics
- 2009

We apply the dynamical systems tools to study the linear dynamics of a self-interacting scalar field trapped on a DGP brane. The simplest kinds of self-interaction potentials are investigated: (a)…

Ghosts in asymmetric brane gravity and the decoupled stealth limit

- Physics
- 2009

We study the spectrum of gravitational perturbations around a vacuum de Sitter brane in a 5D asymmetric braneworld model, with induced curvature on the brane. This generalises the stealth…

Cosmological perturbations on the Phantom brane

- Physics
- 2016

We obtain a closed system of equations for scalar perturbations in a multi-component braneworld. Our braneworld possesses a phantom-like equation of state at late times, $w_{\rm eff} < -1$, but no…

Randall-Sundrum brane cosmology: Modification of late-time cosmic dynamics by exotic matter

- Physics
- 2011

In this paper we show, through the study of concrete examples, that depending on the cosmic dynamics of the energy density of matter degrees of freedom living in the brane, Randall–Sundrum (RS) brane…

Generalized ghost dark energy in DGP model

- PhysicsInternational Journal of Geometric Methods in Modern Physics
- 2019

In 2000, Dvali et al. [4-D gravity on a brane in 5-D Minkowski space, Phys. Lett. B 485 (2000) 208–214] proposed a new braneworld model named as DGP model, having two branches with [Formula: see…

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