General-relativistic coupling between orbital motion and internal degrees of freedom for inspiraling binary neutron stars
General-relativistic coupling between orbital motion and internal degrees of freedom for inspiraling binary neutron stars
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吸气双中子星轨道运动与内部自由度之间的广义相对论耦合
DOI：
10.1103/physrevd.58.124030
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发表时间：
1997
影响因子：
5
通讯作者：
E. Flanagan
中科院分区：
文献类型：
--
作者：
E. Flanagan
分析了密近双星中子星内部自由度与轨道运动的耦合。我们的分析是基于匹配渐近展开的方法，对每个星星内部引力强度的所有阶数都有效，但在"潮汐膨胀参数“（恒星半径）/（轨道间距）方面是微扰的。在一阶潮汐膨胀参数下，我们证明了每颗星星的内部结构不受其伴星的影响，这与A.怀斯曼[Phys. Rev. 79，1189（1997）]。我们还表明，相对论性的相互作用，规模作为更高的权力的潮汐膨胀参数产生定性类似的影响，他们的牛顿同行：每个星星的牛顿潮汐畸变都有修正，这两个修正都发生在潮汐膨胀参数的第三级，每个星星的中心密度都有牛顿减小的修正（牛顿的“潮汐稳定”），两者都是潮汐膨胀参数的六阶。有额外的相互作用，没有牛顿的类似物，但这些并没有改变每个星星的中心密度高达六阶的潮汐膨胀参数。这些结果，结合以前对牛顿潮汐相互作用的分析，表明：（i）在动力学轨道不稳定性之前，不存在可能导致恒星坍缩成黑洞的大的广义相对论性破碎力;（ii）关于合并双中子星作为引力波爆发源的传统观点是正确的：也就是说，对引力波形的有限恒星大小的修正对于探测聚并来说并不重要。
We analyze the coupling between the internal degrees of freedom of neutron stars in a close binary and the stars' orbital motion. Our analysis is based on the method of matched asymptotic expansions and is valid to all orders in the strength of internal gravity in each star, but is perturbative in the ``tidal expansion parameter'' (stellar radius)/(orbital separation). At first order in the tidal expansion parameter, we show that the internal structure of each star is unaffected by its companion, in agreement with post-1-Newtonian results of A. Wiseman [Phys. Rev. Lett. 79, 1189 (1997)]. We also show that relativistic interactions that scale as higher powers of the tidal expansion parameter produce qualitatively similar effects to their Newtonian counterparts: there are corrections to the Newtonian tidal distortion of each star, both of which occur at third order in the tidal expansion parameter, and there are corrections to the Newtonian decrease in the central density of each star (Newtonian ``tidal stabilization''), both of which are sixth order in the tidal expansion parameter. There are additional interactions with no Newtonian analogues, but these do not change the central density of each star up to sixth order in the tidal expansion parameter. These results, in combination with previous analyses of Newtonian tidal interactions, indicate that (i) there are no large general-relativistic crushing forces that could cause the stars to collapse to black holes prior to the dynamical orbital instability and (ii) the conventional wisdom with respect to coalescing binary neutron stars as sources of gravitational-wave bursts is correct: namely, finite-stellar-size corrections to the gravitational waveform will be unimportant for the purpose of detecting coalescences.