Grand unified brane world scenario

We present a field theoretical model unifying grand unified theory (GUT) and brane world scenario. As a concrete example, we consider SU(5) GUT in 4 + 1 dimensions where our 3 + 1 dimensional spacetime spontaneously arises on five domain walls. A field-dependent gauge kinetic term is used to localize massless non-Abelian gauge fields on the domainwalls and to assure the charge universality of matter fields. We find the domain wallswith the symmetry breaking SU(5) -> SU(3) x SU(2) x U(1) as a globalminimumand all the undesirablemoduli are stabilized with themass scale of M-GUT. Profiles ofmassless standardmodel particles are determined as a consequence of wall dynamics. The proton decay can be exponentially suppressed.