1. Accretion of the degenerate Fermi gas onto a Reissner-Nordstr\'{o}m black hole
- Author
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Li, Ping, Yang, Jiang-he, and Xu, Siwei
- Subjects
General Relativity and Quantum Cosmology - Abstract
We investigate the stationary, spherically symmetric accretion of a degenerate relativistic Fermi gas onto a Reissner-Nordstr\"{o}m black hole. The accretion theory is based on the Boyer-Lindquist coordinates and the Fermi gas follows Fermi-Dirac statistics at infinity. We have derived the expression for the particle current density, the stress energy-momentum tensor, and three accretion rates. As the charged particle falls into the black hole, both the mass and the charge of the black hole increase. Consequently, the mass accretion rate and charge accretion rate are proportional to the particle accretion rate. We have also provided analytical results at infinity and numerical results within a finite range for these quantities. Our results indicate that the accretion rate decreases as the charge of the black hole increases, suggests that the presence of naked singularities is avoided in black hole accretion theory. In this paper, we also discovered that the accretion model of Vlasov gas behaves as an anisotropic fluid containing two perfect-fluid components. One component represents the isotropic fluid of Fermi gas, while the other represents a null fluid. When using the Boyer-Lindquist coordinate system, we observed that the contribution from the null fluid persists even at infinity, which led to the radial pressure always smaller than the tangential pressure. Therefore, it's not appropriate to treat the accretion model as a perfect fluid at infinity.
- Published
- 2024