Schwinger-Dyson equations for gauge-invariant correlators
  The formalism for Schwinger-Dyson equations of Wilson loops, as developed by Eguchi, Weingarten, and Foerster, is extended to include connected correlators. These should allow one to study propagators and interactions of glueball fields without having to handle gauge dependent fields such as gluons an ghosts. Some steps towards a solution are made. 
David Vercauteren
hep-th