Two-loop scattering amplitudes: double-forward limit and colour-kinematics duality

oleh: Yvonne Geyer, Ricardo Monteiro, Ricardo Stark-Muchão

Format: Article
Diterbitkan: SpringerOpen 2019-12-01

Deskripsi

Abstract We propose new formulae for the two-loop n-point D-dimensional integrands of scattering amplitudes in Yang-Mills theory and gravity. The loop integrands are written as a double-forward limit of tree-level trivalent diagrams, and are inferred from the formalism of the two-loop scattering equations. We discuss the relationship between the formulae for non-supersymmetric theories and the Neveu-Schwarz sector of the formulae for maximally supersymmetric theories, which can be derived from ambitwistor strings. An important property of the loop integrands is that they are expressed in a representation that includes linear-type propagators. This representation exhibits a loop-level version of the colour- kinematics duality, which follows directly from tree level via the double-forward limit.