A Closer Look at Two $Ad{S}_4$ Branes in an $Ad{S}_5$ Bulk

We investigate a scenario with two $Ad{S}_4$ branes in an $Ad{S}_5$ bulk. In this scenario there are two gravitons and we investigate the role played by each of them for different positions of the second brane. We show that both gravitons play a significant role only when the turn-around point in the warp factor is approximately equidistant from both branes. We find that the ultralight mode becomes heavy as the second brane approaches the turn-around point, and the physics begins to resemble that of the RS model. Thus we demonstrate the crucial role played by the turn-around in the warp factor in enabling the presence of both gravitons.