Massless gravitons on a brane from massive gravity in five-dimensional Minkowski space

Abstract

We discuss the possibility of localizing Einstein gravity on a three-brane embedded in a five-dimensional Minkowski space by giving a space-dependent mass to the graviton. We show that, with an overall fine tuning of the mass profile, it is possible to localize a massless graviton with a finite mass gap from the massive Kaluza-Klein modes. The theory does not contain ghosts and no scalar massless mode is sourced by brane matter. A massless vector mode is strongly coupled to the flux of energy-momentum into the extra dimension, so that it is not sourced as long as only brane-localized matter is considered. In the case where the mass profile has a delta-like shape the four-dimensional Planck mass $M_4$ is related to the five-dimensional one, $M_5$, by $M_4^{2}=M_5^3/m_0$, where $m_0$ is the mass of the first Kaluza-Klein mode of the graviton.