One-loop effective potential for the vacuum gauge field in $M_3\times S^3\times S^1$ space-times

We calculate the effective potential for the vacuum gauge field from the one-loop matter effect in $M_3\times S^3\times S^1$ space-time. This background geometry is motivated from the recent studies on gauged supergravities with a positive-definite potential, which admits a generalized Kaluza-Klein reduction. We investigate how symmetry breaking patterns through the Hosotani mechanism are affected by the ratio of the radii of $S^1$ and $S^3$.