Topological Effects in Our Brane World From Extra Dimensions

TL;DR

This paper explores how topological defects like cosmic strings and monopoles can form in brane world models with extra dimensions, acting as windows to the higher-dimensional space and revealing novel physical phenomena.

Contribution

It introduces the concept of topologically stable defects arising from spontaneous symmetry breaking in extra dimensions, highlighting their unique core structures and implications for brane world scenarios.

Findings

Existence of topologically stable defects such as cosmic strings and monopoles in brane models.

Defects act as 'windows' to extra dimensions due to restored translation invariance in their cores.

Analogous to Alice strings, encircling these defects can transport one onto a parallel brane.

Abstract

The theories in which our world presents a domain wall (brane) embedded in large extra dimensions predict new types of topological defects. These defects arise due to the fact that the brane on which we live spontaneously breaks isometries of the extra space giving mass to some graviphotons. In many cases the corresponding vacuum manifold has nontrivial homotopies -- this gives rise to topologically stable defects in four dimensions, such as cosmic strings and monopoles that carry gravimagnetic flux. The core structure of these defects is somewhat peculiar. Due to the fact that the translation invariance in the extra direction(s) is restored in their core, they act as "windows" to the extra dimensions. We also discuss the corresponding analog of the Alice strings. Encircling such an object one would get transported onto a parallel brane.