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arXiv 2006.07962hep-thgr-qc
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二维渐近平坦时空中的非奇异黑洞

Nonsingular black hole in two-dimensional asymptotically flat spacetime

Wen-Yuan Ai

摘要:

本文用拉格朗日量$\mathcal{L}=\frac{1}{2}\sqrt{-g}(ϕR+{λ^2}{\rm sech}^2ϕ)$研究了一种特殊的二维引力场,其中$λ$是维质量参数。这个理论描述了渐近平坦的二维时空。非常有趣的是,它有一个度量的精确解,$\d s^2=-(c+\tanh λx)\d t^2+ \d x^2/(c+\tanh λ x)$,由$c$参数化。对于$c\in(-1,1)$,该解决方案提供了一个事件视界,但没有奇异性。由于解中出现的度规分量的扭折轮廓,我们把度规描述的时空称为{ \it引力域壁},该壁简单地是事件视界,并将两个渐近闵可夫斯基时空分开。通过坐标延拓研究了这类物体的全局因果结构,并计算了相应的物理量。只有当$c\in(-1,0]$是熵和能量非负时。

英文摘要:

We study a special two-dimensional dilaton gravity with Lagrangian $\mathcal{L}=\frac{1}{2}\sqrt{-g}(ϕR+{λ^2}{\rm sech}^2ϕ)$ where $λ$ is a parameter of dimension mass. This theory describes two-dimensional spacetimes that are asymptotically flat. Very interestingly, it has an exact solution for the metric, $\d s^2=-(c+\tanh λx)\d t^2+ \d x^2/(c+\tanh λ x)$, parametrized by $c$. For $c\in(-1,1)$, the solution presents an event horizon but no singularity. Because of the kink profile for the metric components appearing in the solution, we refer to the spacetime described by the metric as a {\it gravitational domain wall} with the wall simply being the event horizon and separating two asymptotically Minkowskian spacetimes. The global causal structure for such an object is studied via coordinate extension and the thermodynamical quantities are computed. Only when $c\in(-1,0]$ are the entropy and energy non-negative.

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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