标题： 关于旋转玻色子星中的动力学条形模不稳定性 显示英文标题

标题： On the dynamical bar-mode instability in spinning bosonic stars

摘要： 旋转的玻色子星（SBSs）可以从具有非零角动量的稀薄标量/Proca粒子云的引力坍缩中形成。 在最近的工作中，我们发现标量星由于一种非轴对称不稳定性而具有短暂性，这种不稳定性会引发角动量的损失。 我们进一步利用三维数值相对论模拟研究了SBSs的动力学形成过程，这些模拟涉及爱因斯坦-（大质量、复数）克莱因-戈登系统和爱因斯坦-（复数）Proca系统。 在标量情况下，我们引入了一个四次自相互作用势能，以评估其对不稳定性的影响；我们研究了（m=2）Proca星以评估其稳定性；我们尝试将SBSs的不稳定性与方位密度模式的增长率以及共转点的存在联系起来。 我们表明：自相互作用势能只能延迟标量SBSs中的不稳定性；m=2 Proca星总是会迁移到稳定的m=1球形家族；不稳定的m=2 Proca星和m=1标量玻色子星表现出一个共转点。 这与受动态棒状模不稳定性影响的旋转中子星形成了类比。 我们计算了发出的引力波（GWs），并研究了波形的可探测性，通过将信号的特征应变与各种探测器的灵敏度曲线进行比较，计算信噪比。 假设SBSs中棒状变形的特征阻尼时间尺度仅由引力波辐射决定，而不是由粘滞作用（不同于中子星），我们发现坍缩后的辐射可能比棒状模不稳定性本身的辐射能量高几个数量级。 我们的结果表明，SBSs的引力波观测可能在未来的实验范围内，为确立此类恒星的存在和对玻色子粒子的质量施加严格限制提供了一种潜在手段。 显示英文摘要

摘要： Spinning bosonic stars (SBSs) can form from the gravitational collapse of a dilute cloud of scalar/Proca particles with non-zero angular momentum. In a recent work we found that the scalar stars are transient due to a non-axisymmetric instability which triggers the loss of angular momentum. We further study the dynamical formation of SBSs using 3-dimensional numerical-relativity simulations of the Einstein-(massive, complex)Klein-Gordon system and of the Einstein-(complex)Proca system. We incorporate a quartic self-interaction potential in the scalar case to gauge its effect on the instability; we investigate (m=2) Proca stars to assess their stability; we attempt to relate the instability of SBSs to the growth rate of azimuthal density modes and the existence of a corotation point. We show that: the self-interaction potential can only delay the instability in scalar SBSs; m=2 Proca stars always migrate to the stable m=1 spheroidal family; unstable m=2 Proca stars and m=1 scalar boson stars exhibit a corotation point. This establishes a parallelism with rotating neutron stars affected by dynamical bar-mode instabilities. We compute the gravitational waves (GWs) emitted and investigate the detectability of the waveforms comparing the characteristic strain of the signal with the sensitivity curves of a variety of detectors, computing the signal-to-noise ratio. By assuming that the characteristic damping timescale of the bar-like deformation in SBSs is only set by GWs emission and not by viscosity (unlike in neutron stars), we find that the post-collapse emission could be orders of magnitude more energetic than that of the bar-mode instability itself. Our results indicate that GW observations of SBSs might be within the reach of future experiments, offering a potential means to establish the existence of such stars and to place tight constraints on the mass of the bosonic particle.