Self-Dual Point and Unification

TL;DR

This paper explores the idea that the vacuum state in string theory shifts from the self-dual point, leading to new unification mechanisms of gauge couplings in higher-dimensional models near this special point.

Contribution

It proposes a novel hypothesis that the vacuum is near the self-dual point, enabling unique gauge unification solutions in higher-dimensional string models not seen in four-dimensional theories.

Findings

Unification solutions near the self-dual point in higher-dimensional models.

Vacuum shifts from the self-dual point lead to new unification scenarios.

Models with branes in higher dimensions can realize these unification solutions.

Abstract

We hypothesize that the vacuum is spontaneously shifted from the self-dual point in the moduli space, at which all dimensions are compact, and that the true vacuum results from the decompactification of the four space-time dimensions and remains in the vicinity of the self-dual point for extra dimensions. On the basis of our hypotheses we explore new types of the coupling unification which are not realized in the four-dimensional effective theory but in the framework of the higher dimensional theory. In the $SU(6) \times SU(2)_R$ string model, if the SU(6) gauge group lives in the world-volume of 9-branes and the $SU(2)_R$ in the world-volume of 5-branes, or {\it vice versa}, unification solutions can be found in the vicinity of the self-dual point.