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 th e brane world actually is a likely description of nature. Our discussion in cludes a revisit of certain issues, namely, coupling unification, dilaton s tabilization and supersymmetry breaking, in the context of the brane world scenario. In particular, we discuss various possible string scenarios and t heir phenomenological implications in the brane world framework. (C) 1999 E lsevier Science B.V. All rights reserved.