On amplitudes in Chiral Higher Spin Gravity

TL;DR

This paper derives and classifies cubic amplitudes in Chiral Higher Spin Gravity, confirming their agreement with previous light-cone gauge results and demonstrating that all tree-level amplitudes vanish in a specific truncation.

Contribution

It provides a covariant derivation of cubic interactions, classifies all possible cubic amplitudes from twistor theory, and solves recursion relations for a higher-spin extension of self-dual Yang-Mills.

Findings

Cubic amplitudes agree with light-cone gauge results.

All tree-level amplitudes vanish in the studied truncation.

Propagators for arbitrary spin are derived in Feynman/Lorenz gauges.

Abstract

We extract cubic interactions from the covariant equations of motion of Chiral Higher Spin Gravity and compute the corresponding amplitudes. These amplitudes are found to agree with earlier results obtained in the light-cone gauge. We also classify all possible cubic amplitudes that can be constructed from chiral fields arising in twistor theory. In addition, we derive propagators for arbitrary spin in the Feynman/Lorenz gauges. These propagators are then used to solve Berends--Giele recursion relations for a truncation of Chiral Higher Spin Gravity, which is a higher-spin extension of self-dual Yang--Mills theory. We confirm that all tree-level amplitudes vanish.