# Detecting dark energy in orbit: The cosmological chameleon

@article{Brax2004DetectingDE, title={Detecting dark energy in orbit: The cosmological chameleon}, author={P. Brax and C. V. D. Bruck and A. Davis and J. Khoury and A. Weltman}, journal={Physical Review D}, year={2004}, volume={70}, pages={123518} }

We show that the chameleon scalar field can drive the current phase of cosmic acceleration for a large class of scalar potentials that are also consistent with local tests of gravity. These provide explicit realizations of a quintessence model where the quintessence scalar field couples directly to baryons and dark matter with gravitational strength. We analyze the cosmological evolution of the chameleon field and show the existence of an attractor solution with the chameleon following the… Expand

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#### References

SHOWING 1-10 OF 88 REFERENCES

Interacting Dark Matter and Dark Energy

- Physics
- 2003

We discuss models for the cosmological dark sector in which the energy density of a scalar field approximates Einstein's cosmological constant and the scalar field value determines the dark matter… Expand

Chameleon Cosmology

- Physics
- 2003

The evidence for the accelerated expansion of the Universe and the time dependence of the fine-structure constant suggests the existence of at least one scalar field with a mass of order H0. If such… Expand

Baryon bias and structure formation in an accelerating universe

- Physics
- 2002

In most models of dark energy the structure formation stops after the accelerated expansion begins. In contrast, we show that the coupling of dark energy to dark matter may induce the growth of… Expand

Quantum effects and stability of chameleon cosmology

- Physics
- 2004

One possibility to explain the current accelerated expansion of the universe may be related with the presence of cosmologically evolving scalar whose mass depends on the local matter density… Expand

The Cosmon model for an asymptotically vanishing time dependent cosmological 'constant'

- Physics
- 1994

We investigate the coupled system of gravity and a scalar with exponential potential. The energy momentum tensor of the scalar field induces a time-dependent cosmological “constant”. This adjusts… Expand

Cosmological tracking solutions

- Physics
- 1999

A substantial fraction of the energy density of the universe may consist of quintessence in the form of a slowly rolling scalar field. Since the energy density of the scalar field generally decreases… Expand

Coupled Quintessence

- Physics
- 1999

A new component of the cosmic medium, a light scalar field or ”quintessence ”, has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant. Such a field is… Expand

Models of quintessence coupled to the electromagnetic field and the cosmological evolution of alpha

- Physics
- 2004

We study the change of the effective fine structure constant in the cosmological models of a scalar field with a non-vanishing coupling to the electromagnetic field. Combining cosmological data and… Expand

Stationary dark energy: The Present universe as a global attractor

- Physics
- 2001

We propose a cosmological model that makes a significant step toward solving the coincidence problem of the near similarity at the present of the dark energy and dark matter components. Our cosmology… Expand

Cosmological variation of the fine structure constant from an ultralight scalar field: The effects of mass

- Physics
- 2003

Cosmological variation of the fine structure constant a due to the evolution of a spatially homogeneous ultralight scalar field (m;H0) during the matter and L dominated eras is analyzed. Agreement of… Expand