Topology, normalisability and the Schr\"odinger equation: Compact QED   (2+1)
  For the special case of compact QED in (2+1) dimensions, we calculate the non-Gaussian vacuum wave-functional to second order in the monopole fugacity and obtain the effective photon mass. Our method presents some hope for understanding the connection between variational and systematic approaches to understanding the non-perturbative wave-functional. 
David Nolland