# Relativistic dust accretion of charged particles in Kerr-Newman spacetime

## TL;DR

This paper introduces an analytical model for plasma accretion onto a charged, rotating black hole, highlighting how even tiny black hole charges can significantly influence plasma dynamics and accretion disc structure.

## Contribution

It generalizes an existing accretion model to include black hole charge and analyzes its effects on plasma motion and disc configuration.

## Key findings

- Small black hole charge can significantly affect plasma trajectories.
- Accretion disc edges depend strongly on plasma charge.
- Even negligible electromagnetic fields can influence plasma accretion.

## Abstract

We describe a new analytical model for the accretion of particles from a rotating and charged spherical shell of dilute collisionless plasma onto a rotating and charged black hole. By assuming a continuous injection of particles at the spherical shell and by treating the black hole and a featureless accretion disc located in the equatorial plane as passive sinks of particles we build a stationary accretion model. This may then serve as a toy model for plasma feeding an accretion disc around a charged and rotating black hole. Therefore, our new model is a direct generalization of the analytical accretion model introduced by E. Tejeda, P. A. Taylor, and J. C. Miller (2013). We use our generalized model to analyze the influence of a net charge of the black hole, which will in general be very small, on the accretion of plasma. Within the assumptions of our model we demonstrate that already a vanishingly small charge of the black hole may in general still have a non-negligible effect on the motion of the plasma, as long as the electromagnetic field of the plasma is still negligible. Furthermore, we argue that the inner and outer edges of the forming accretion disc strongly depend on the charge of the accreted plasma. The resulting possible configurations of accretion discs are analyzed in detail.