# Grand Unified Brane World Scenario

## TL;DR

This paper proposes a unified field theoretical model combining grand unified theories with brane world scenarios, demonstrating how our 4D universe can emerge on domain walls with localized gauge fields, stabilizing moduli and suppressing proton decay.

## Contribution

It introduces a concrete 5D $SU(5)$ GUT model with domain walls that localize Standard Model particles and gauge fields, unifying GUT and brane world concepts with stabilized moduli.

## Key findings

- Domain walls with $SU(5)\to SU(3)\times SU(2)\times U(1)$ symmetry breaking as a global minimum
- Massless Standard Model particles localized on the walls
- Exponential suppression of proton decay

## Abstract

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 $SU(5)\to SU(3)\times SU(2)\times U(1)$ as a global minimum and all the undesirable moduli are stabilized with the mass scale of $M_{\rm GUT}$. Profiles of massless Standard Model particles are determined as a consequence of wall dynamics. The proton decay can be exponentially suppressed.