How to tell a gravastar from a black hole
How to tell a gravastar from a black hole
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DOI：
10.1088/0264-9381/24/16/013
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发表时间：
2007-06
影响因子：
3.5
通讯作者：
C. Chirenti;L. Rezzolla
中科院分区：
文献类型：
--
作者：
C. Chirenti;L. Rezzolla
引力星最近被提出作为解释传统上与黑洞相关的天体物理现象的潜在替代方案，提出了这两个物体是否可以区分的问题。撇开辩论的过程，将导致形成的引力星和天文证据在他们的支持，在这里，我们解决两个基本问题：是一个引力星稳定对一般的扰动？如果它是稳定的，观察者能将它与相同质量的黑洞区分开来吗？为了回答这些问题，我们构建了一个一般类的引力星，并确定它们必须满足的条件，以存在的爱因斯坦方程的平衡解。对于这样的模型，我们进行了系统的稳定性分析，对轴向扰动，计算本征频率的真实的和虚部。总的来说，我们发现引力星是稳定的轴向扰动，而且它们的准正常模式不同于相同质量的黑洞，因此可以用来辨别，毫无疑问，引力星从黑洞。
Gravastars have been recently proposed as potential alternatives to explain the astrophysical phenomenology traditionally associated with black holes, raising the question of whether the two objects can be distinguished at all. Leaving aside the debate about the processes that would lead to the formation of a gravastar and the astronomical evidence in their support, here we address two basic questions: is a gravastar stable against generic perturbations? If it is stable, can an observer distinguish it from a black hole of the same mass? To answer these questions we construct a general class of gravastars and determine the conditions they must satisfy in order to exist as equilibrium solutions of the Einstein equations. For such models we perform a systematic stability analysis against axial perturbations, computing the real and imaginary parts of the eigenfrequencies. Overall, we find that gravastars are stable to axial perturbations, but also that their quasi-normal modes differ from those of a black hole of the same mass and thus can be used to discern, beyond dispute, a gravastar from a black hole.