Supergravity black holes, Love numbers, and harmonic coordinates
Supergravity black holes, Love numbers, and harmonic coordinates
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DOI：
10.1103/physrevd.105.084035
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发表时间：
2021-09
影响因子：
5
通讯作者：
M. Cvetič;G. Gibbons;C. Pope;B. Whiting
中科院分区：
文献类型：
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作者：
M. Cvetič;G. Gibbons;C. Pope;B. Whiting
为了对引力理论进行实际的测试，我们需要能够超越广义相对论，用观测数据来评估替代理论的一致性，特别是使用例如不可知论的贝叶斯方法进行引力波探测。在本文中，我们进一步研究了一类这样可行的，替代理论的性质，基于度量产生自未测量的超重力。特别地，我们研究了一般稳态轴对称背景度规（如带电旋转黑洞的背景度规）中无质量、中性、最小耦合标量波动方程，当标量场是时间无关的或处于低频、近区极限时，以计算潮汐扰动的Love数，并获得背景度规的调和坐标。对于非测量超引力理论的四参数带电渐近平坦旋转黑洞解，即STU黑洞，其中包括kaluzza - klein黑洞和KerrSen黑洞作为特殊情况，我们发现所有时间无关的解，以及度量的调和坐标，都与Kerr解的调和坐标相同。在低频极限下，我们发现标量场表现出与克尔解相同的SL（2， R）对称性。我们指出我们的结果扩展到更广泛的度量类，其中包括爱因斯坦-麦克斯韦-膨胀理论的解。
To perform realistic tests of theories of gravity, we need to be able to look beyond general relativity and evaluate the consistency of alternative theories with observational data from, especially, gravitational wave detections using, for example, an agnostic Bayesian approach. In this paper we further examine properties of one class of such viable, alternative theories, based on metrics arising from ungauged supergravity. In particular, we examine the massless, neutral, minimally coupled scalar wave equation in a general stationary, axisymmetric background metric such as that of a charged rotating black hole, when the scalar field is either time independent or in the low-frequency, nearzone limit, with a view to calculating the Love numbers of tidal perturbations, and of obtaining harmonic coordinates for the background metric. For a four-parameter family of charged asymptotically flat rotating black hole solutions of ungauged supergravity theory known as STU black holes, which includes Kaluza-Klein black holes and the KerrSen black hole as special cases, we find that all time-independent solutions, and hence the harmonic coordinates of the metrics, are identical to those of the Kerr solution. In the low-frequency limit we find the scalar fields exhibit the same SL(2, R) symmetry as holds in the case of the Kerr solution. We point out extensions of our results to a wider class of metrics, which includes solutions of Einstein-Maxwell-Dilaton theory.