  We discuss the motivation and the phenomenology of models with either flat or
warped extra dimensions. We describe the typical mass spectrum and discovery
signatures of such models at the LHC. We also review several proposed methods
for discriminating the usual low-energy supersymmetry from a model with flat
(universal) extra dimensions. (For the official website of the book, see
http://cambridge.org/us/catalogue/catalogue.asp?isbn=9780521763684 .)
