Brane World

In string theory, the brane world scenario, where the Standard Model gauge and matter fields live inside some branes while gravitons live in the bulk, can be a viable description of our universe. In this note we argue that the brane world actually is a likely description of nature. Our discussion includes a revisit of certain issues, namely, coupling unification, dilaton stabilization and supersymmetry breaking, in the context of the brane world scenario. In particular, we discuss various possible string scenarios and their phenomenological implications in the brane world framework.