Scattering amplitudes have their origin in quantum field theory, but have wide-ranging
applications extending to classical physics. We review a formalism to connect certain …

The double copy is, in essence, a map between scattering amplitudes in a broad variety of
familiar field and string theories. In addition to the mathematically rich intrinsic structure, it …

The classical double copy relates exact solutions of gauge, gravity, and other theories.
Although widely studied, its origins and domain of applicability have remained mysterious. In …

A bstract The three-point amplitude is the key building block in the on-shell approach to
scattering amplitudes. We show that the classical objects computed by massive three-point …

A bstract The Weyl double copy is a procedure for relating exact solutions in biadjoint scalar,
gauge and gravity theories, and relates fields in spacetime directly. Where this procedure …

A bstract Many gauge theories possess a hidden duality between color and kinematics in
their on-shell scattering amplitudes. An open problem is to formulate an off-shell realization …

A bstract In the standard derivation of the Kerr-Schild double copy, the geodicity of the Kerr-
Schild vector and the stationarity of the spacetime are presented as assumptions that are …

A bstract The double copy suggests that the basis of the dynamics of general relativity is
Yang-Mills theory. Motivated by the importance of the relativistic two-body problem, we study …

We establish the status of the Weyl double copy relation for radiative solutions of the vacuum
Einstein equations. We show that all type N vacuum solutions, which describe the radiation …

A bstract We give a double copy construction for the symmetries of the self-dual sectors of
Yang-Mills (YM) and gravity, in the light-cone formulation. We find an infinite set of double …