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arXiv 1804.09413astro-ph.HEgr-qc
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从完美测量极限的引力波看中子星的天震学

Astroseismology of neutron stars from gravitational waves in the limit of perfect measurement

Arthur G Suvorov

摘要:

受扰中子星的振荡谱与星的物理性质(如状态方程)密切相关。因此,观测脉动的中子星可以对这些物理性质加以限制。然而,从这些测量中究竟能学到多少并不明显。如果我们观察足够长的时间,足够精确,有可能了解关于恒星的一切吗?光谱几何理论中的一个经典结果表明,人们不能唯一地“听到鼓的形状”。更正式地说,它是已知的,一个本征频谱可能不会唯一地对应于一个特定的几何形状;一些“鼓”可能是无法区分的,从正常模式的角度来看。与此相反,我们表明,鼓的结果并不延伸到扰动的简单中子星在广义相对论-在轴向(环形)扰动的情况下,静态的,完美的流体星,准正常模式谱唯一对应的恒星轮廓。我们在本文中表明,这是不可能的两个中子星,具有不同的流体剖面,以相同的方式振荡。这个结果具有信息论的推论,即引力波完全编码了任何给定振荡星的性质:在完美测量的极限下,唯一的识别是可能的。

英文摘要:

The oscillation spectrum of a perturbed neutron star is intimately related to the physical properties of the star, such as the equation of state. Observing pulsating neutron stars therefore allows one to place constraints on these physical properties. However, it is not obvious exactly how much can be learnt from such measurements. If we observe for long enough, and precisely enough, is it possible to learn everything about the star? A classical result in the theory of spectral geometry states that one cannot uniquely `hear the shape of a drum'. More formally, it is known that an eigenfrequency spectrum may not uniquely correspond to a particular geometry; some `drums' may be indistinguishable from a normal-mode perspective. In contrast, we show that the drum result does not extend to perturbations of simple neutron stars within general relativity -- in the case of axial (toroidal) perturbations of static, perfect fluid stars, a quasi-normal mode spectrum uniquely corresponds to a stellar profile. We show in this paper that it is not possible for two neutron stars, with distinct fluid profiles, to oscillate in an identical manner. This result has the information-theoretic consequence that gravitational waves completely encode the properties of any given oscillating star: unique identifications are possible in the limit of perfect measurement.

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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