---
Masato Arai
---
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 domain walls
and to assure the charge universality of
matter fields. We find the domain walls with
the symmetry breaking SU(5)->SU(3)0SU(2)0U(1)
as a global minimum and all the undesirable
moduli are stabilized with the mass scale
of M_GUT. Profiles of massless Standard Model
particles are determined as a consequence
of wall dynamics. The proton decay can be
exponentially suppressed.

---