The Double Copy Structure of Soft Gravitons

TL;DR

This paper reveals a double copy structure in soft graviton corrections to scattering amplitudes, connecting gauge theories and gravity, and extends classical theorems to high-energy regimes with non-soft gravitons.

Contribution

It uncovers a double copy structure in subleading soft graviton corrections and extends Gribov's theorem to high-energy nonabelian gauge theories and gravity.

Findings

Double copy structure in soft graviton contributions

Extension of Gribov's theorem to high energies

Subleading corrections derived from Low's theorem

Abstract

The subleading corrections to factorization theorems for soft bremsstrahlung in nonabelian gauge theories and gravity are investigated in the case of a five point amplitude with four scalars. Building on recent results, we write the action of the angular momentum operators on scattering amplitudes as derivatives with respect to the Mandelstam invariants to uncover a double copy structure in the contribution of the soft graviton to the amplitude, both in the leading term and the first correction. Using our approach, we study Gribov's theorem as extended to nonabelian gauge theories and gravity by Lipatov, and find that subleading corrections can be obtained from those to Low's theorem by dropping the terms with derivatives with respect to the center-of-mass energy, which are suppressed at high energies. In this case, the emitted gravitons are not necessarily soft.