D-Brane Probes of G_2 Holonomy Manifolds
  We describe how mirror symmetry of three-dimensional N=1 supersymmetric gauge theories can be used to determine the theory on the world-volume of a D2-brane probe of manifolds with G_2 holonomy. This is a much shortened companion paper to hep-th/0202126. 
Sergei Gukov and David Tong