Ghafran Khan | Searcharxiv

arXiv2025

A Monte Carlo approach to stationary kinetic disks in the Kerr spacetime

We extend a recently proposed Monte Carlo scheme for computing stationary solutions of the general-relativistic Vlasov equation to the Kerr spacetime. As an example, we focus on razor-thin configurations of a gas confined to the equatorial plane and extending to spatial infinity. We consider monoenergetic models as well as solutions corresponding to planar Maxwell-J\"{u}ttner distributions at infinity. In both cases, the components of the particle current surface density are recovered within the proposed Monte Carlo framework. Some aspects of razor-thin kinetic disk models, including an analysis of the bulk angular momentum and angular velocity, are briefly covered.

gr-qc↗

arXiv2025

Finite collisionless accretion disks in the Kerr spacetime

We construct general-relativistic kinetic models of stationary finite accretion disks in the Kerr spacetime. Our analysis generalizes a previous model of razor-thin accretion disks of collisionless gas in the Kerr spacetime, extending to infinity in the equatorial plane. We investigate monoenergetic configurations, as well as models characterized by Maxwell-J\"{u}ttner type distributions at the outer edge of the disk. In both cases, we consider particles moving along orbits reaching the outer boundary of the disk, either plunging into the black hole, or scattered by the centrifugal barrier. For Maxwell-J\"{u}ttner models, the location of the outer disk boundary affects the mass and angular momentum accretion rates at a similar order of magnitude as the temperature parameter in the assumed Maxwell-J\"{u}ttner distribution.

gr-qc↗