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arXiv 2601.22015gr-qc
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Schwarzschild黑洞格林函数的分解

Decomposition of Schwarzschild Green's Function

Tsinghua University(清华大学);Universität Leipzig(莱比锡大学);University College Dublin(都柏林大学学院);Centro Brasileiro de Pesquisas Físicas (CBPF)(巴西物理研究 Centro Brasileiro de Pesquisas Físicas (CBPF));Perimeter Institute for Theoretical Physics(理论物理前沿研究所)

Junquan Su, Neev Khera, Marc Casals, Sizheng Ma, Abhishek Chowdhuri, Huan Yang

AI总结:

本文通过将格林函数分解为G^+和G^-两个部分,分析其在复频率平面的解析结构,揭示了分支割线、迟滞尾和准正常模谱的物理意义。

摘要:

我们提出了一个基于将格林函数分解为两个部分G^+和G^-的Schwarzschild黑洞球形分解格林函数的公式,这两个部分根据其高频行为进行划分。尽管类似的分解之前已有考虑,但此处我们系统地将其应用于Schwarzschild时空,并分析其对格林函数在复频率平面解析结构的影响。我们证明G^+和G^-都沿虚轴具有分支割线,导致直接部分和迟滞尾,而G^+的极点对应于准正常模谱。这使得我们能够通过适应不同因果时空区域的轮廓来识别分支割线直接部分、准正常模贡献和迟滞尾。这与Leaver的原始公式形成鲜明对比,其中即时响应与技术上困难的大弧贡献相关。我们通过独立的时间域Regge-Wheeler模拟验证了我们的分解,发现有很好的一致性。我们的结果提供了一个实用且物理上透明的框架,用于分离Schwarzschild响应的不同部分,并为扩展到Kerr扰动和非线性环下物理提供了自然的起点。

英文摘要:

We present a formulation of the spherically decomposed Green's function for a Schwarzschild black hole, based on a decomposition into two components, $G^+$ and $G^-$, based on their large-frequency behaviour. While similar decompositions have been considered previously, here we systematically apply it to Schwarzschild spacetime and analyze its implications for the analytic structure of the Green's function in the complex-frequency plane. We show that both $G^+$ and $G^-$ possess branch cuts along the imaginary axis, which give rise to the direct part and the late-time tail, while the poles of $G^+$ correspond to the quasinormal mode spectrum. This allows us to identify a $\textit{branch-cut direct part}$, a quasinormal-mode contribution, and a late-time tail through contours adapted to different causal spacetime regions. This is in sharp contrast to Leaver's original formulation, where the prompt response is tied to a technically difficult large-arc contribution. We validate our decomposition with independent time-domain Regge-Wheeler simulations finding excellent agreement. Our results provide a practical and physically transparent framework for disentangling the distinct pieces of the Schwarzschild response, and offer a natural starting point for extensions to Kerr perturbations and non-linear ringdown physics.

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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