Precessing binary black holes as engines of electromagnetic helicity
Abstract
We show that binary black hole mergers with precessing evolution can potentially excite photons from the quantum vacuum in such a way that total helicity is not preserved in the process. Helicity violation is allowed by quantum fluctuations that spoil the electricmagnetic duality symmetry of the classical Maxwell theory without charges. We show here that precessing binary black hole systems in astrophysics generate a flux of circularly polarized gravitational waves which, in turn, provides the required helical background that triggers this quantum effect. Solving the fully nonlinear Einstein's equations with numerical relativity we explore the parameter space of binary systems and extract the detailed dependence of the quantum effect with the spins of the two black holes. We also introduce a set of diagrammatic techniques that allows us to predict when a binary black hole merger can or cannot emit circularly polarized gravitational radiation, based on mirrorsymmetry considerations. This framework allows to understand and to interpret correctly the numerical results, and to predict the outcomes in potentially interesting astrophysical systems.
 Publication:

Physical Review D
 Pub Date:
 August 2023
 DOI:
 10.1103/PhysRevD.108.044052
 arXiv:
 arXiv:2303.15534
 Bibcode:
 2023PhRvD.108d4052S
 Keywords:

 General Relativity and Quantum Cosmology
 EPrint:
 Minor update