Persistent black holes in bouncing cosmologies
Persistent black holes in bouncing cosmologies
复制标题
DOI：
10.1088/1361-6382/aa6dbb
复制
发表时间：
2017-01
影响因子：
3.5
通讯作者：
T. Clifton;B. Carr;A. Coley
中科院分区：
文献类型：
--
作者：
T. Clifton;B. Carr;A. Coley
在这篇论文中，我们探讨了黑洞可以在宇宙中持续存在的想法，宇宙坍缩到一个大的紧缩，然后反弹到一个新的膨胀阶段。我们使用标量场来模拟这样一个宇宙在反弹时间附近的物质含量，并在动态宇宙学中寻找代表黑洞网络的解决方案。我们发现爱因斯坦的约束方程，提供了在最小的膨胀空间的几何形状的精确解，可以用作超球形宇宙学的演化的初始数据。这些解决方案说明，存在多个不同黑洞可以通过反弹持续存在的模型，并且允许具体计算黑洞填充因子等量。然后，我们考虑在平坦宇宙学的解决方案，以及在高维空间（多达九个空间维度）。我们推导出黑洞保持不同（即避免合并）的条件，从而持续到新的膨胀阶段。这些模型的一些潜在的有趣的后果也进行了讨论。
In this paper we explore the idea that black holes can persist in a universe that collapses to a big crunch and then bounces into a new phase of expansion. We use a scalar field to model the matter content of such a universe near the time of the bounce, and look for solutions that represent a network of black holes within a dynamical cosmology. We find exact solutions to Einstein’s constraint equations that provide the geometry of space at the minimum of expansion and that can be used as initial data for the evolution of hyperspherical cosmologies. These solutions illustrate that there exist models in which multiple distinct black holes can persist through a bounce, and allow for concrete computations of quantities such as the black hole filling factor. We then consider solutions in flat cosmologies, as well as in higher-dimensional spaces (with up to nine spatial dimensions). We derive conditions for the black holes to remain distinct (i.e. avoid merging) and hence persist into the new expansion phase. Some potentially interesting consequences of these models are also discussed.