English

$\kappa$-Dirac stars

General Relativity and Quantum Cosmology 2023-11-27 v2 High Energy Physics - Theory

Abstract

In this paper, we construct a Dirac star model composed of κ|\kappa| pairs of spinor fields. The azimuthal harmonic indeces mm of these spinor fields are half-integers, and they satisfiy (κ12)mκ12-(|\kappa|-\frac{1}{2})\leq m \leq |\kappa|-\frac{1}{2}. When κ=1\kappa=1, it corresponds to the conventional Dirac star model, formed by two spinor fields with m=12m=\frac{1}{2} and m=12m=-\frac{1}{2}. When κ>1|\kappa|>1, among these κ|\kappa| pairs of spinor fields, there exist spinor fields with azimuthal harmonic indices m>12m>\frac{1}{2}, and all spinor fields still conform to the same Dirac field equation. Different families of solutions are distinguished by the value of κ\kappa, so we named these solutions κ\kappa-Dirac stars. We obtain solutions for κ=±1,±2,±3,±4,±5,±6\kappa=\pm1,\pm2,\pm3,\pm4,\pm5,\pm6 by using numerical methods. Additionally, we compute their ADM mass MM, Noether charge QQ, and binding energy EE, and illustrate how these quantities change with the spinor field's frequency ω\omega for different κ\kappa. We observe significant differences between solutions for κ>1|\kappa|>1 and the κ=1|\kappa|=1 case. Furthermore, we provide the energy density distribution of the Dirac stars, wherein for κ>1|\kappa|>1 scenarios, the Dirac stars exhibit a spherical shell-like structure. Moreover, we employ three-dimensional diagrams to intuitively depict how κ\kappa influences the combination of spinor fields to form a spherically symmetric configuration.

Cite

@article{arxiv.2310.10267,
  title  = {$\kappa$-Dirac stars},
  author = {Shi-Xian Sun and Si-Yuan Cui and Long-Xing Huang and Yong-Qiang Wang},
  journal= {arXiv preprint arXiv:2310.10267},
  year   = {2023}
}

Comments

19 pages, 5 figures. The case of negative value $\kappa$ added, and some discussion expanded

R2 v1 2026-06-28T12:51:49.569Z