Exploring the small mass limit of stationary black holes in theories with Gauss–Bonnet terms
Exploring the small mass limit of stationary black holes in theories with Gauss–Bonnet terms
复制标题
用高斯-邦内项理论探索静止黑洞的小质量极限
DOI：
10.1088/1361-6382/aca010
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发表时间：
2022
影响因子：
3.5
通讯作者：
J. F. Delgado
中科院分区：
文献类型：
--
作者：
Pedro G S Fernandes;D. Mulryne;J. F. Delgado
在这项工作中，我们研究了小质量极限的黑洞（BH），有和没有自旋，在理论中的标量场是非最小耦合到高斯-邦纳（GB）项。首先，我们提供了一个分析的例子，一个静态的封闭形式的解决方案与一个小的质量限制的理论是已知的，后来使用分析和数值技术来探索这个限制在标准的标量GB理论与标量，线性和二次指数耦合。在这里研究的大多数情况下，我们发现一个内部的奇异性，重叠的事件视界的静态BH的小质量极限达到。此外，由于在这个极限下的解具有非零的霍金温度，预计通过蒸发会达到裸奇点，这引起了关于这些理论一致性的问题。另一方面，我们第一次在这种情况下提供了一个耦合的例子，其中的小质量极限是永远不会达到的，因此从宇宙审查的角度来看，首选。最后，我们考虑具有自旋的黑洞，并数值研究这如何改变图像，使用这些来为膨胀和线性理论的耦合常数设定迄今为止最严格的上限，其中α <1 km。
In this work we examine the small mass limit of black holes (BHs), with and without spin, in theories where a scalar field is non-minimally coupled to a Gauss–Bonnet (GB) term. First, we provide an analytical example for a theory where a static closed-form solution with a small mass limit is known, and later use analytical and numerical techniques to explore this limit in standard scalar-GB theories with dilatonic, linear and quadratic-exponential couplings. In most cases studied here, we find an inner singularity that overlaps with the event horizon of the static BH as the small mass limit is reached. Moreover, since solutions in this limit possess a non-vanishing Hawking temperature, a naked singularity is expected to be reached through evaporation, raising questions concerning the consistency of these theories altogether. On the other hand, we provide for the first time in this context an example of a coupling where the small mass limit is never reached, thus preferred from the point of view of cosmic censorship. Finally, we consider BHs with spin and numerically investigate how this changes the picture, using these to place the tightest upper bounds to date on the coupling constant for the dilatonic and linear theories, with α‾<1 km.