Comment on "Construction of regular black holes in general relativity"

Abstract

It is claimed that the paper by Zhong-Ying Fan and Xiaobao Wang [Phys. Rev. D 94, 124027 (2016), arXiv: 1610.02636] on nonlinear electrodynamics coupled to general relativity, being correct in general, in some respects repeats previously obtained results without giving proper references. There is also an important point missing in this paper, but necessary for understanding the physics of the system: in solutions with an electric charge, a regular center requires a non-Maxwell behavior of the Lagrangian function $L(f),(f=F_{\mu \nu }{F}^{\mu \nu })$ at small $f$. Therefore, in all electric regular black hole solutions with a Reissner-Nordström asymptotic, the Lagrangian $L(f)$ is different in different parts of space, and the electromagnetic field behaves in a singular way at surfaces where $L(f)$ suffers branching.

3 pages, no figures. arXiv admin note: text overlap with arXiv:1708.08125

References in corpus (2)

• Construction of Regular Black Holes in General Relativity
• Regular black holes in an asymptotically de Sitter universe

Cited by in corpus (3)

• Testing Rotating Regular Metrics as Candidates for Astrophysical Black Holes
• Relaxations of perturbations of spacetimes in general relativity coupled to nonlinear electrodynamics
• Quasinormal modes, shadow and greybody factors of 5D electrically charged Bardeen black holes