Double copies of fermions as only gravitational interacting matter

TL;DR

This paper explores hypothetical fermionic particles that interact solely via gravity, using double copy methods inspired by recent advances in scattering amplitudes, and provides two computational approaches for their scattering amplitudes.

Contribution

It introduces a novel class of fermionic particles as double copies of gauge fields, expanding the double copy framework to new matter types with gravitational-only interactions.

Findings

Two equivalent methods for computing scattering amplitudes of these particles

Particles can be massive and non-relativistic

Interactions are purely gravitational

Abstract

Inspired by the recent progress in the field of scattering amplitudes, we discuss hypothetical particles which can be characterised as the double copies of fermions -- in the same way gravitons can be viewed as double copies of gauge bosons. As the gravitons, these hypothetical particles interact only through gravitational interactions. We present two equivalent methods for the computation of the relevant scattering amplitudes. The hypothetical particles can be massive and non-relativistic.