Physical Review D 74,8 (2006) 085007;
Gauge theories embedded into higher-dimensional spaces with certain topologies acquire inductance terms, which reflect the energy cost of topological charges accumulated in the extra dimensions. We compute topological susceptibility in the strongly-coupled two-flavor massive Schwinger model with such an inductance term and find that it vanishes, due to the contribution of a global low-energy mode (a "global axion"). This is in accord with the general argument on the absence of theta dependence in such topologies. Because the mode is a single oscillator, there is no corresponding particle, and the solution to the U(1) problem is unaffected.
cp conservation;; invariance;; vacuum
Date of this Version