D-brane field theory on compact spaces
  We consider Dirichlet p-branes in type II string theory on a space which has been toroidally compactified in d dimensions. We give an explicit construction of the field theory description of this system by putting a countably infinite number of copies of each brane on the noncompact covering space, and modding out the resulting gauge theory by Z^d. The resulting theory is a gauge theory with graded fields corresponding to strings winding around the torus an arbitrary number of times. In accordance with T-duality, this theory is equivalent to the gauge theory for the dual system of (d + p)-branes wrapped around the compact directions, where the winding number is exchanged for momentum in the compact direction. 
Washington Taylor (Princeton U.)