Braneworld is a new scenario of compactification of extra-dimensions. In this scenario the extension of extra-dimensions is assumed to be relatively large compared with Planck scale. In the usual scheme of Kalza-Klein compactification large extra-dimensions mean presence of many light particles, which contradicts with experiments. However, recently people realized the possibility that ordinary matter fields can be localized on a low dimensional object called brane. In that case, directions orthogonal to the brane are not sensed by ordinary matter fields. Then even if we consider higher dimensional models with relatively large extra-dimensions, the models can be consistent with observations. On the other hand, since spacetime is extended, gravity propagates in a higher dimensional spacetime, which we call bulk. Fortunately or unfortunately, gravity is so weak. Hence, the deviation from the standard Newton's law has not been severely tested below sub-mm scale.
My collaborators and I studied
gravity in braneworld mainly in
RS II model,
and clarified how the prediction of braneworld
deviates from the standard general relativity.
Another aspect on which I'm working is quantum correction
to the brane dynamics. It is well known that
Casimir force arises between two parallel plates.
Analogous phenomena happens in the context of braneworld.
This force may play a role to stabilize the distance between branes.
Gravitational radiation reaction