English

Can accretion properties distinguish between a naked singularity, wormhole and black hole?

General Relativity and Quantum Cosmology 2020-12-29 v1

Abstract

We first advance a mathematical novelty that the three geometrically and topologically distinct objects mentioned in the title can be exactly obtained from the Jordan frame vacuum Brans I solution by a combination of coordinate transformations, trigonometric identities and complex Wick rotation. Next, we study their respective accretion properties using the Page-Thorne model which studies accretion properties exclusively for rrmsr\geq r_{\text{ms}} (the minimally stable radius of particle orbits), while the radii of singularity/ throat/ horizon r<rmsr<r_{\text{ms}}. Also, its Page-Thorne efficiency ϵ\epsilon is found to increase with decreasing rmsr_{\text{ms}} and also yields ϵ=0.0572\epsilon=0.0572 for Schwarzschild black hole (SBH). But in the singular limit rrsr\rightarrow r_{s} (radius of singularity), we have ϵ1\epsilon\rightarrow 1 giving rise to 100%100 \% efficiency in agreement with the efficiency of the naked singularity constructed in [10]. We show that the differential accretion luminosity dLdlnr\frac{d\mathcal{L}_{\infty}}{d\ln{r}} of Buchdahl naked singularity (BNS) is always substantially larger than that of SBH, while Eddington luminosity at infinity LEddL_{\text{Edd}}^{\infty} for BNS could be arbitrarily large at rrsr\rightarrow r_{s} due to the scalar field ϕ\phi that is defined in (rs,)(r_{s}, \infty). It is concluded that BNS accretion profiles can still be higher than those of regular objects in the universe.

Keywords

Cite

@article{arxiv.2012.13564,
  title  = {Can accretion properties distinguish between a naked singularity, wormhole and black hole?},
  author = {R. Kh. Karimov and R. N. Izmailov and A. A. Potapov and K. K. Nandi},
  journal= {arXiv preprint arXiv:2012.13564},
  year   = {2020}
}

Comments

17 pages, 12 figures