Effective actions of a Gauss–Bonnet brane world with brane curvature terms

AbstractWe consider a warped brane world scenario with two branes, Gauss–Bonnet gravity in the bulk, and brane localised curvature terms. When matter is present on both branes, we investigate the linear equations of motion and distinguish three regimes. At very high energy and for an observer on the positive tension brane, gravity is four-dimensional and coupled to the brane bending mode in a Brans–Dicke fashion. The coupling to matter and brane bending on the negative tension brane is exponentially suppressed. In an intermediate regime, gravity appears to be five dimensional while the brane bending mode remains four-dimensional. At low energy, matter on both branes couple to gravity for an observer on the positive tension brane, with a Brans–Dicke description similar to the 2-brane Randall–Sundrum setup. We also consider the zero mode truncation at low energy and show that the moduli approximation fails to reproduce the low energy action