# Is the radion a chameleon?

@article{Brax2004IsTR, title={Is the radion a chameleon?}, author={Philippe Brax and Carsten van de Bruck and A. C. Davis}, journal={Journal of Cosmology and Astroparticle Physics}, year={2004}, volume={2004}, pages={004 - 004} }

The chameleon mechanism is a way to give an effective mass to a light scalar field via field self-interaction and interaction with matter. We study this mechanism in models in which the couplings are field dependent and find that the properties are very different from the case of constant couplings. The consequences of a runaway potential for the radion field in brane world scenarios and whether the radion can play the role of dark energy is investigated. The cosmological evolution during the…

## 39 Citations

### Towards a UV completion of chameleons in string theory

- Mathematics
- 2011

Chameleons are scalar fields that couple directly to ordinary matter with gravitational strength, but which nevertheless evade the stringent constraints on tests of gravity because of properties they…

### Dilaton stabilization and composite dark matter in the string frame of heterotic-M-theory

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- 2012

In this paper we further elaborate on our recently proposed solution to the cosmological constant problem - Phys. Rev. D82 (2010) 044006. One of the elements of the solution is the chameleonic…

### The cosmological constant problem in heterotic-M-theory and the orbifold of time

- Physics
- 2016

Chameleon fields are quantum fields with an increasing mass as a function of the matter density of the environment. Recently chameleon fields have been exploited to solve the cosmological constant…

### Cosmological perturbations during radion stabilization

- Physics
- 2005

We consider the evolution of cosmological perturbations during radion stabilization, which we assume to happen after a period of inflation in the early universe. Concentrating on the Randall-Sundrum…

### Towards a UV Completion for Chameleon Scalar Theories

- Physics
- 2010

Chameleons are scalar fields that couple directly to ordinary matter with gravitational strength, but which nevertheless evade the stringent constraints on tests of gravity because of properties they…

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- Physics
- 2016

In this letter we investigate the role played by quantum mechanics before the big-bang in heterotic-M-theory assuming an orbifold compactification of time. As we will see particles are localized…

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- Physics
- 2006

A braneworld model for neutrino dark energy (DE) is presented. We consider a five-dimensional two-branes setup with a bulk scalar field motivated by supergravity. Its low-energy effective theory is…

### Tests of chameleon gravity

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- 2018

The present state-of-the-art searches for screened scalars coupled to matter are summarized, and the current bounds on f(R) models that exhibit the chameleon mechanism are translated into a single parametrization to survey the state of the models.

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