Ringing the Randall-Sundrum braneworld: Metastable gravity wave bound states

In the Randall-Sundrum scenario, our universe is a 4-dimensional "brane" living in a 5-dimensional bulk spacetime. By studying the scattering of bulk gravity waves, we show that this brane rings with a characteristic set of complex quasinormal frequencies, much like a black hole. To a bulk observer these modes are interpreted as metastable gravity wave bound states, while a brane observer views them as a discrete spectrum of decaying massive gravitons. Potential implications of these scattering resonances are discussed.