Brane Mechanism of Spontaneously Generated Gravity

Abstract

The braneworld scenario is studied and the effective action of 3-brane living in 5-dim. Minkowski space is constructed. This action is proved to be invariant under spontaneously broken scale and Weyl symmetries and to encode a model of quadratic gravity generalizing the Starobinsky model. The symmetry breaking generates the Hilbert-Einstein term with the Newton constant $G_{N}\sim\frac{1}{\mu^{2}}$, where $\mu$ is a mass scale equal to the mean curvature of the vacuum hyper-worldsheet of 3-brane. This result proposes a brane modification of the mechanism of spontaneously generated gravity.