## Abstract

A generic second-order scalar-tensor theory contains a nonlinear derivative self-interaction of the scalar degree of freedom à la Galileon models, which allows for the Vainshtein screening mechanism. We investigate this effect on subhorizon scales in a cosmological background, based on the most general second-order scalar-tensor theory. Our analysis takes into account all the relevant nonlinear terms and the effect of metric perturbations consistently. We derive an explicit form of Newton's constant, which in general is time-dependent and hence is constrained from observations, as suggested earlier. It is argued that in the most general case the inverse-square law cannot be reproduced on the smallest scales. Some applications of our results are also presented.

Original language | English |
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Article number | 024023 |

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 85 |

Issue number | 2 |

DOIs | |

Publication status | Published - Jan 13 2012 |

Externally published | Yes |

## All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)