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arXiv 2503.03345gr-qcastro-ph.HE
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后牛顿中子星的微扰理论

Perturbation theory for post-Newtonian neutron stars

Fabian Gittins, Nils Andersson, Shanshan Yin

AI总结:

本研究为模拟中子星动力学的后牛顿微扰理论建立了厄米拉格朗日框架,导出守恒辛积、正则能量及模式正交性条件,并证明公式唯一性,为双星旋进晚期动力学潮汐建模奠定基础。

摘要:

中子星是致密的相对论性天体,承载着现代物理学的多个极端。近年来的一个令人振奋的发展是,通过使用灵敏的引力波和电磁仪器观测致密双星并合,有机会探测这种奇异物理。为了最大化从这些测量中推断出的科学成果,我们需要能够准确表示物理的模型。在本研究中,我们考虑广义相对论的后牛顿近似来模拟中子星动力学,特别着眼于模拟双星旋进晚期阶段的动力学潮汐。我们为非旋转恒星建立了后牛顿微扰方程,并证明该微扰问题是厄米的,因此源自一个基本拉格朗日量。建立这一拉格朗日系统导致微扰存在守恒的辛积和正则能量。我们确定了后牛顿振荡模式的正交性条件,这反过来构成了常用于动力学潮汐的模式求和表示的基础。最后,我们证明了该微扰公式是唯一的。

英文摘要:

Neutron stars are compact, relativistic bodies that host several extremes of modern physics. An exciting development in recent years has been the opportunity to probe this exotic physics by observing compact-binary coalescences using sensitive gravitational-wave and electromagnetic instruments. To maximise the science inferred from these measurements, we require models that accurately represent the physics. In this study, we consider the post-Newtonian approximation to general relativity for the modelling of neutron-star dynamics, with a particular view to model dynamical tides at the late stages of binary inspiral. We develop the post-Newtonian perturbation equations for a non-rotating star and show that the perturbation problem is Hermitian and therefore derives from a fundamental Lagrangian. Establishing this Lagrangian system leads to a conserved symplectic product and canonical energy for the perturbations. We determine the orthogonality condition for the post-Newtonian oscillation modes, which in turn forms the foundation of a mode-sum representation often used for dynamical tides. Finally, we demonstrate that the perturbation formulation is unique.

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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