Astronomy, University of Southampton,*

*SO17 1BJ Southampton, United Kingdom*

Introduction
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Symmetry breaking plays an important role in particle physics. In the Standard Model (SM), the scalar Higgs field, is charged under the local gauged $SU(2)\times U(1)$ symmetry and acquires a vacuum expectation value (VEV) order parameter. In extra dimensions, gauge symmetries may be broken by the presence of background gauge fields on non-simply connected manifolds, a phenomenon known as the Hosotani mechanism [@Hosotani:1983xw; @Hosotani:1983vn], or Wilson-line symmetry breaking [@Candelas:1985en]. It is based on the Aharonov-Bohm observation that in the presence of a non-contractible loop, a gauge field can not always be gauged away and leads to shifts of momenta with observable effects. This mechanism is an extra dimensional version of spontaneous symmetry breaking (SSB), in which the extra dimensional components of gauge fields can effectively develop VEVs.

The idea of Wilson lines has been applied to the Higgs mechanism of the SM, in an approach known as Gauge-Higgs Unification (GHU) [@Sakamura:2007qz; @Medina:2007hz; @Hall:2001zb; @Gogoladze:2003bb; @Hosotani:2006qp; @Scrucca:2003ut; @Antoniadis:2001cv; @Panico:2005dh]. This assumes extra dimensions with the Higgs boson coming from the extra dimensional part of the gauge fields. However this idea is severely challenged since it relates the compactification scale with 