Color-kinematics duality and dimensional reduction for graviton emission in Regge limit
Henrik Johansson, Agustin Sabio Vera, Eduardo Serna Campillo, Miguel A. Vazquez-Mozo
TL;DR
This work investigates how color-kinematics duality and the BCJ double-copy can be extended to graviton emission in the Regge limit for scattering of two scalars. It identifies two viable extensions— a scalar contact interaction from dimensional reduction of higher-dimensional pure Yang-Mills and the use of indistinguishable adjoint scalars—that permit duality-compatible numerators to reproduce Lipatov's graviton-emission vertex. In both cases the gravitational amplitude constructed by double-copy matches Lipatov's effective vertex in the multi-Regge kinematics, supporting a higher-dimensional origin for the duality in matter-rich theories. The results point toward embedding gauge/gravity theories in higher dimensions as a consistent pathway to general matter content, with open questions about fermions and scalars.
Abstract
In this talk we review the work in [1,2,3] where we have studied the applicability of the color-kinematics duality to the scattering of two distinguishable scalar matter particles with one gluon emission in QCD, or one graviton emission in Einstein gravity. We have shown that the duality works well in the Regge limit under two different extensions of the gauge theory: the introduction of a new scalar contact interaction and the relaxation of the distinguishability of the scalars. Both modifications correspond to theories obtained by dimensional reduction from higher-dimensional pure gauge theories.