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arXiv 2405.09124gr-qc
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用正则中心替代黑洞反弹

A regular center instead of a black bounce

S. V. Bolokhov, K. A. Bronnikov, M. V. Skvortsova

AI总结:

本文针对球对称时空奇点消除问题,提出构建$r=0$正则中心的修改方法,将其推广至更一般时空,得到Fisher解与伸缩子黑洞的正则修改,并在GR框架下分析了其场源性质。

摘要:

由Simpson和Visser提出的、被广泛讨论的用于消除球对称时空中$r=0$处奇点的“黑洞反弹(black-bounce)”机制,其核心是移除$r=0$点及其紧邻邻域,从而产生一个球半径的正则最小值,该最小值可以是虫洞喉道或是正则反弹。与之不同的是,近期有研究提出通过适当修改度规,使$r=0$成为一个正则中心,同时仍保留其在远离$r=0$区域的形式。针对几类奇点,研究者已经构建出了不同的此类修改算法。此前的论文研究了里奇张量满足条件$R^t_t =R^r_r$的时空,并针对Schwarzschild度规、Reissner-Nordström度规,以及两个服从非线性电动力学(NED)的含磁场解的例子,得到了正则修改结果。本文研究了更具一般性的时空的正则修改,并作为示例,针对具有裸奇点的Fisher(也称为JNW)解以及一类伸缩子黑洞,得到了带正则中心的修改结果。在广义相对论(GR)的框架下,利用“任何静态球对称度规都可对应包含NED和带有某种自相互作用势的标量场的组合源”这一事实,本文研究了新正则度规的可能场源。一般而言,该标量场不需要是幻影性质的(这与黑洞反弹的源不同),但在本文讨论的例子中,可能的标量源在$r=0$的紧邻邻域内是幻影的,而在其外部则是正则的。

英文摘要:

The widely discussed ``black-bounce'' mechanism of removing a singularity at $r=0$ in a spherically symmetric space-time, proposed by Simpson and Visser, consists in removing the point $r=0$ and its close neighborhood, resulting in emergence of a regular minimum of the spherical radius that can be a wormhole throat or a regular bounce. Instead, it has been recently proposed to make $r=0$ a regular center by properly modifying the metric, still preserving its form in regions far from $r=0$. Different algorithms of such modifications have been formulated for a few classes of singularities. The previous paper considered space-times whose Ricci tensor satisfies the condition $R^t_t =R^r_r$, and regular modifications were obtained for the Schwarzschild, Reissner-Nordström metrics, and two examples of solutions with magnetic fields obeying nonlinear electrodynamics (NED). The present paper considers regular modifications of more general space-times, and as examples, modifications with a regular center have been obtained for the Fisher (also known as JNW) solution with a naked singularity and a family of dilatonic black holes. Possible field sources of the new regular metrics are considered in the framework of general relativity (GR), using the fact that any static, spherically symmetric metric with a combined source involving NED and a scalar field with some self-interaction potential. This scalar field is, in general, not required to be of phantom nature (unlike the sources for black bounces), but in the examples discussed here, the possible scalar sources are phantom in a close neighborhood of $r=0$ and are canonical outside it.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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