Magnetic Field Probe of the No-Hair Theorem

Understand

We discuss the consequences of violating the no-hair theorem on magnetic fields surrounding a black hole.

• This is achieved by parametrically deforming the Kerr spacetime and studying the effects of such deformations on asymptotically uniform magnetic fields around the black hole.
• We compute the deformed electromagnetic field for slow spins and small deformation parameter, and show that the correction is of order the deformation parameter and mimics the angular structure of a quadrupole.