标题： 旋转相对论星体中的动力学非轴对称不稳定性 显示英文标题

标题： Dynamical non-axisymmetric instabilities in rotating relativistic stars

摘要： 我们提出了关于快速旋转中子星中动力不稳定性的新结果。 特别是，使用完整的广义相对论数值模拟，我们分析了恒星致密性对动力条形模不稳定性开始阈值以及其他动力不稳定性出现的影响。 通过使用在我们之前的研究所开发和测试的外推技术[1]，我们明确确定了由59个恒星模型组成的四个常重子质量模型序列在广泛致密范围内的阈值。 我们的阈值计算与牛顿预测相符，并改进了之前的后牛顿估计。 此外，我们发现对于质量足够大且致密的恒星，m=3变形是增长最快的。 对于所有考虑的模型，非轴对称不稳定性在动力学时间尺度上被抑制，m=1变形主导了不稳定性最后阶段。 这些结果与[1]中呈现的结果一起表明，在完全广义相对论和牛顿引力中，m=1变形代表了非轴对称动力不稳定性的一般且晚期特征。 显示英文摘要

摘要： We present new results on dynamical instabilities in rapidly rotating neutron-stars. In particular, using numerical simulations in full General Relativity, we analyse the effects that the stellar compactness has on the threshold for the onset of the dynamical bar-mode instability, as well as on the appearance of other dynamical instabilities. By using an extrapolation technique developed and tested in our previous study [1], we explicitly determine the threshold for a wide range of compactnesses using four sequences of models of constant baryonic mass comprising a total of 59 stellar models. Our calculation of the threshold is in good agreement with the Newtonian prediction and improves the previous post-Newtonian estimates. In addition, we find that for stars with sufficiently large mass and compactness, the m=3 deformation is the fastest growing one. For all of the models considered, the non-axisymmetric instability is suppressed on a dynamical timescale with an m=1 deformation dominating the final stages of the instability. These results, together with those presented in [1], suggest that an m=1 deformation represents a general and late-time feature of non-axisymmetric dynamical instabilities both in full General Relativity and in Newtonian gravity.