Properties of an electrically charged black hole in Eddington-inspired Born-Infeld gravity
Properties of an electrically charged black hole in Eddington-inspired Born-Infeld gravity
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DOI：
10.1103/physrevd.90.124087
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发表时间：
2014-12
影响因子：
5
通讯作者：
H. Sotani;U. Miyamoto
中科院分区：
文献类型：
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作者：
H. Sotani;U. Miyamoto
我们系统地研究了Eddington-inspired Born-Infeld引力下带电黑洞的性质，不仅考虑了理论中的正耦合常数，而且考虑了负耦合常数。因此，我们在数值上发现，即使存在负耦合常数，黑洞的电荷也可能大于黑洞的质量，黑洞解仍然存在。我们还澄清了黑洞解存在的参数空间。另一方面，为了研究这种黑洞周围的粒子运动，我们导出了测地线方程。粒子径向运动的有效势的行为几乎与广义相对论中相同，但最内层稳定圆轨道的半径和给出最内层稳定圆轨道的角动量可以改变，这取决于耦合常数。特别地，我们发现在耦合常数特定值下，最内层稳定圆轨道的半径可以小于广义相对论中极端情况下的半径。这种粒子释放的引力结合能比广义相对论预测的要多，这从观测的角度来看可能是重要的。
We systematically examine the properties of an electrically charged black hole in Eddington-inspired Born-Infeld gravity with not only the positive but also the negative coupling constant in the theory. As a result, we numerically find that the black hole solution exists even with the negative coupling constant, where the electric charge of black hole can be larger than the black hole mass. We also clarify the parameter space where the black hole solution exists. On the other hand, to examine the particle motion around such black hole, we derive the geodesic equation. The behavior of the effective potential for the radial particle motion is almost the same as that in general relativity, but the radius of the innermost stable circular orbit and the angular momentum giving the innermost stable circular orbit can be changed, depending on the coupling constant. In particular, we find that the radius of innermost stable circular orbit with the specific value of the coupling constant can be smaller than that for the extreme case in general relativity. Such a particle can release the gravitational binding energy more than the prediction in general relativity, which could be important from the observational point of view.