Universality of the Blandford-Znajek emission in stationary and axisymmetric spacetimes
Phys. Rev. D 114, 023014 – Published 10 July, 2026
DOI: https://doi.org/10.1103/8b1s-5mmm
Abstract
The Blandford-Znajek (BZ) mechanism is widely recognized as the most compelling process to extract rotational energy from an accreting black hole and power the emission of relativistic jets. We explore the universality of this process for generic black-hole spacetimes within the Konoplya-Rezzolla-Zhidenko formalism and find that the lowest-order contribution to the BZ power is invariant across different black-hole spacetimes. We also show that, at the next-leading order, different black-hole spacetimes will lead to different BZ luminosities. As a result, while slowly rotating black holes cannot be distinguished via measurements of their jet power, rapidly rotating ones have the potential of providing information on the strong-field properties of the spacetime when independent measurements of the BZ luminosity and of the black-hole angular velocity are available.
