Abstract

A Hayward black hole and a magnetically charged black hole based on rational nonlinear electrodynamics with the Lagrangian \({\mathcal{L}}={-}{\mathcal{F}}/(1+2\beta{\mathcal{F}})\) (\({\mathcal{F}}\) is the field invariant) are considered. It is shown that the metric function in both models possesses a de Sitter core without singularities as \(r\to 0\). The behavior of the Hawking temperature and the heat capacity in these models are similar. The phase transitions take place when the Hawking temperature has a maximum, and black holes are thermodynamically stable at some event horizon radii when the heat capacity is positive. We show that the source of gravity in the Hayward model is questionable.

中文翻译：

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关于具有理性非线性电动力学的海沃德和磁化黑洞非奇异模型的评论

摘要

基于拉格朗日\（{\ mathcal {L}} = {-} {\ mathcal {F}} /（1 + 2 \ beta {\ mathcal {F }}）\）（\（{\ mathcal {F}} \）是字段不变的）。结果表明，两个模型中的度量函数都具有de Sitter核心，没有奇异值\（r \ to 0 \）。这些模型中的霍金温度行为和热容相似。当霍金温度达到最高时，发生相变；当热容为正时，黑洞在某些事件范围半径处具有热力学稳定性。我们证明了海沃德模型中的引力来源是可疑的。