English

The Weyl Double Copy for Gravitational Waves

High Energy Physics - Theory 2025-12-16 v3 General Relativity and Quantum Cosmology

Abstract

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 region of isolated gravitational systems with appropriate fall-off for the matter fields, admit a degenerate Maxwell field that squares to give the Weyl tensor. This relation defines a scalar that satisfies the wave equation on the background. We show that for non-twisting radiative solutions, the Maxwell field and the scalar also satisfy the Maxwell equation and the wave equation on Minkowski spacetime. Hence, non-twisting solutions have a straightforward double copy interpretation.

Keywords

Cite

@article{arxiv.2010.02925,
  title  = {The Weyl Double Copy for Gravitational Waves},
  author = {Hadi Godazgar and Mahdi Godazgar and Ricardo Monteiro and David Peinador Veiga and C. N. Pope},
  journal= {arXiv preprint arXiv:2010.02925},
  year   = {2025}
}

Comments

Accepted for publication in Phys. Rev. Lett

R2 v1 2026-06-23T19:05:57.520Z