Accurate numerical simulations of inspiralling binary neutron stars and their comparison with effective-one-body analytical models
Accurate numerical simulations of inspiralling binary neutron stars and their comparison with effective-one-body analytical models
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吸气双中子星的精确数值模拟及其与有效单体分析模型的比较
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发表时间：
2011
期刊：
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通讯作者：
L. Rezzolla
中科院分区：
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作者：
L. Baiotti;T. Damour;B. Giacomazzo;A. Nagar;L. Rezzolla
中子星双星系统是最有希望的引力波源之一。为了能够提取重要的信息，特别是关于核密度下的物质状态方程，有必要掌握预期波形的准确分析模型。根据我们最近的工作[L。贝奥蒂，T。达穆尔，B。Giacomazzo，A. Nagar和L. Rezzolla，Phys. Rev. Lett. 105，261101（2010）.]，在这里，我们更详细地分析了两个广义相对论模拟跨越约20个引力波周期的等质量的双中子星与不同的紧凑性的inspiral，并比较它们与潮汐扩展的有效单体（EOB）的分析模型。后者潮汐扩展EOB模型分析完成了1.5后牛顿的水平，并包含一个分析待定的参数代表了高阶放大的潮汐效应。我们发现，通过校准这个单一的参数，EOB模型可以重现，数值误差内，两个数值波形基本上合并。相比之下，分析模型（无论是EOB或泰勒-T4），不包括这样一个高阶放大的潮汐效应，建立一个退相相对于几个弧度的数值波形。
Binary neutron-star systems represent one of the most promising sources of gravitational waves. In order to be able to extract important information, notably about the equation of state of matter at nuclear density, it is necessary to have in hand an accurate analytical model of the expected waveforms. Following our recent work [L. Baiotti, T. Damour, B. Giacomazzo, A. Nagar, and L. Rezzolla, Phys. Rev. Lett. 105, 261101 (2010).], we here analyze more in detail two general-relativistic simulations spanning about 20 gravitational-wave cycles of the inspiral of equal-mass binary neutron stars with different compactnesses, and compare them with a tidal extension of the effective-one-body (EOB) analytical model. The latter tidally extended EOB model is analytically complete up to the 1.5 post-Newtonian level, and contains an analytically undetermined parameter representing a higher-order amplification of tidal effects. We find that, by calibrating this single parameter, the EOB model can reproduce, within the numerical error, the two numerical waveforms essentially up to the merger. By contrast, analytical models (either EOB or Taylor-T4) that do not incorporate such a higher-order amplification of tidal effects, build a dephasing with respect to the numerical waveforms of several radians.