We demonstrate the formation of magnetically arrested minidisks (MAM) around equal-mass, nonspinning binary black holes with magnetohydrodynamic simulations of circumbinary disk accretion in full 3+1 general relativity. The initial separation of d∼30M allows the black holes to host large minidisks that suppress the total rest-mass accretion rate variability, which is modulated primarily at ∼1.6forb. Each black hole horizon saturates with dimensionless magnetic flux ϕ∼30. Magnetic reconnection near the horizons drives recurrent eruptions which are expected to drive flaring in the infrared and X-ray bands. Our results establish MAMs as a new outcome of circumbinary disk accretion, and a promising source of novel electromagnetic counterparts to gravitational waves from binary black holes.
@article{arxiv.2509.18254,
title = {Binary black holes gone MAD: Magnetically arrested minidisks around nonspinning black holes},
author = {Vikram Manikantan and Vasileios Paschalidis},
journal= {arXiv preprint arXiv:2509.18254},
year = {2025}
}