Can extra dimensional effects allow wormholes without exotic matter?

ABSTRACT

We explore the existence of Lorentzian wormholes in the context of an effective on-brane, scalar-tensor theory of gravity. It is shown that, for a class of wormholes, the required matter, as seen by an on-brane observer in the Jordan frame, is not exotic and does not violate the Weak Energy Condition. The effective geometric stress energy due to the finite radion field is responsible for creating this intriguing possibility. In fact, if such a wormhole is ever found to exist in the Universe, it would clearly be a pointer towards the existence of a warped extra dimension as proposed in the two-brane model of Randall and Sundrum.