Relationship Between Gravity and Gauge Scattering in the High Energy   Limit
  Investigations of high-energy graviton-graviton and gluon-gluon scattering are performed in the leading eikonal approximation for the kinematic regime of large center of mass energy and low momentum transfer. We find a double copy relation between the amplitudes of the two theories to all loop orders when, on the gauge theory side, we retain only the set of diagrams at each loop order for which the collinear divergences cancel amongst themselves. For this to happen the color structure of all diagrams in the set must be identical. Using standard field theoretic methods, it is shown that this relation is reflected in a similar double copy relationship between the classical shockwaves of the two theories as well. 
Ryo Saotome, Ratindranath Akhoury
hep-th