Vainshtein mechanism in second-order scalar-tensor theories

Abstract

In second-order scalar-tensor theories we study how the Vainshtein mechanism works in a spherically symmetric background with a matter source. In the presence of the field coupling $F(\ensuremath{\phi})={e}^{\ensuremath{-}2Q\ensuremath{\phi}}$ with the Ricci scalar $R$ we generally derive the Vainshtein radius within which the general relativistic behavior is recovered even for the coupling $Q$ of the order of unity. Our analysis covers the models such as the extended Galileon and Brans-Dicke theories with a dilatonic field self-interaction. We show that, if these models are responsible for the cosmic acceleration today, the corrections to gravitational potentials are generally small enough to be compatible with local gravity constraints.