Year: 2026
Type: article
Abstract: Cosmic strings that are attached to rapidly spinning black holes can extract significant amounts of rotational energy and angular momentum. Here we study the effect on primordial black holes, which are expected to form with one or more cosmic strings attached. Although large primordial black holes are predicted to rapidly spin up due to accretion soon after forming, we argue that cosmic strings will spin them down again. We show that if there are cosmic strings with tension greater than $10^{-20}$, the spins of large primordial black holes of mass greater than $30 M_\odot$ should consequently be observed to be near zero. We also investigate the effect on a supermassive black hole of capturing a cosmic string and the possibility of observing the subsequent spin down by its effect on a pulsar orbiting the black hole.
DOI: 10.1103/rm9k-sj82
Authors: Sameer Ahmed, Michael Kavic, Steven L. Liebling, Matthew Lippert, Mohammad Mian, John Simonetti
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: National Science Foundation
Awards: Collaborative Proposal: WoU-MMA: Observations of Gravitational Wave Sources Using the Long Wavelength Array, Collaborative Proposal: WoU-MMA: Observations of Gravitational Wave Sources Using the Long Wavelength Array, RUI: Holographic Stars and Stripes, RUI: Holography of Balls, Branes, and Baryons, Magnetized Mergers of Black Holes and Neutron Stars with LES and Neutrino Transport, RUI: Holographic Stars and Stripes, WoU-MMA: Aspects of Compact Object Mergers
OpenAlex ID: W4400517333