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arXiv 2411.04028gr-qcastro-ph.CO
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天体物理随机背景的谱密度

The spectral density of astrophysical stochastic backgrounds

Enis Belgacem, Francesco Iacovelli, Michele Maggiore, Michele Mancarella, Niccolò Muttoni

AI总结:

本文推导致密双星并合随机背景的谱密度,阐明外部参数平均如何消除偏振,并量化有限源散粒噪声导致的偏振与各向异性。

摘要:

我们对并合致密双星叠加所产生的随机背景的谱密度进行了详细推导。我们展示了文献中常用的表达式如何由对双星外部参数(到达时间、偏振角、到达方向和轨道倾角)的平均得出,以及与圆偏振和线偏振相关的 Stokes 参数如何通过这种平均过程被置零。随后,我们考虑了散粒噪声的影响,即对于有限数量源的叠加,这些平均只是近似的;我们展示了它如何产生圆偏振和线偏振(即使对于各向同性背景也是如此)以及空间各向异性,并针对真实的双黑洞和双中子星族群显式计算了这些量。

英文摘要:

We provide a detailed derivation of the spectral density of the stochastic background generated by the superposition of coalescing compact binaries. We show how the expression often used in the literature emerges from an average over the extrinsic parameters of the binaries (times of arrival, polarization angles, arrival directions and orbit inclinations) and how the Stokes parameters related to circular and linear polarization are set to zero by such averaging procedure. We then consider the effect of shot noise, i.e. the fact that for the superposition of a finite number of sources these averages are only approximate, and we show how it generates circular and linear polarizations (even for isotropic backgrounds) as well as spatial anisotropies, and we compute them explicitly for a realistic population of binary black holes and binary neutron stars.

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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