  In this work the connection between vortex condensation in a d-wave
superconductor and the QED$_3$ gauge theory of the pseudogap is elucidated. The
approach taken circumvents the use of the standard Franz-Tesanovic gauge
transformation, borrowing ideas from the path-integral analysis of the
Aharonov-Bohm problem. An essential feature of this approach is that
gauge-transformations which are prohibited on a particular multiply-connected
manifold (e.g. a superconductor with vortices) can be successfully performed on
the universal covering space associated with that manifold.
