Effective monopoles in noncompact lattice QED

Abstract

In currently used lattice formulations of quantum electrodynamics, even though gauge fields are introduced as noncompact degrees of freedom, the constraints of gauge invariance imply that fermion fields are sensitive to features best described by compact or periodic variables such as magnetic monopoles. Results from a quenched simulation are presented, showing the existence of a percolation threshold for monopole current networks near the chiral-symmetry-breaking transition already known to occur from previous studies. Implications for the mechanism driving the chiral transition are discussed.