Path Group in gauge theory and gravity
  Applications of the Path Group (consisting of classes of continuous curves in Minkowski space-time) to gauge theory and gravity are reviewed. Covariant derivatives are interpreted as generators of an induced representation of Path Group. Non-Abelian generalization of Stokes theorem is naturally formulated and proved in terms of paths. Quantum analogue of Equivalence Principle is formulated in terms of Path Group and Feynman path integrals. 
Michael B. Mensky (P.N. Lebedev Physics Institute, Moscow)