Spinning Black Holes Fall in Love.
Spinning Black Holes Fall in Love.
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旋转的黑洞坠入爱河。
DOI：
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发表时间：
2020
影响因子：
8.6
通讯作者：
M. Casals
中科院分区：
文献类型：
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作者：
A. Le Tiec;M. Casals
黑洞是否会因外部引力场而发生潮汐变形，这一悬而未决的问题对基础物理学、天体物理学和引力波天文学都有着深远的影响。勒夫张量描述了天体物理学（Kerr）黑洞等致密天体在外部静态潮汐场中的潮汐变形性。我们证明了所有的爱张量消失相同的Kerr黑洞在非自旋极限或轴对称潮汐扰动。与此相反，我们表明，爱张量一般是非零的旋转黑洞。具体地说，线性秩序的Kerr黑洞的自旋和弱扰动的潮汐场，我们计算的勒夫张量的封闭形式耦合的质量型和电流型四极矩的电型和磁型四极潮汐场。对于一个无量纲的自旋为0.1，非零的四极勒夫张量是0.2 ×10^{-3}，因此表明黑洞是特别“刚性”的致密物体。
The open question of whether a black hole can become tidally deformed by an external gravitational field has profound implications for fundamental physics, astrophysics, and gravitational-wave astronomy. Love tensors characterize the tidal deformability of compact objects such as astrophysical (Kerr) black holes under an external static tidal field. We prove that all Love tensors vanish identically for a Kerr black hole in the nonspinning limit or for an axisymmetric tidal perturbation. In contrast to this result, we show that Love tensors are generically nonzero for a spinning black hole. Specifically, to linear order in the Kerr black hole spin and the weak perturbing tidal field, we compute in closed form the Love tensors that couple the mass-type and current-type quadrupole moments to the electric-type and magnetic-type quadrupolar tidal fields. For a dimensionless spin ∼0.1, the nonvanishing quadrupolar Love tensors are ∼2×10^{-3}, thus showing that black holes are particularly "rigid" compact objects.