Exact Evolution of Discrete Relativistic Cosmological Models
Exact Evolution of Discrete Relativistic Cosmological Models
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DOI：
10.1088/1475-7516/2013/11/010
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发表时间：
2013-09
期刊：
影响因子：
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通讯作者：
T. Clifton;D. Gregoris;K. Rosquist;R. Tavakol
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文献类型：
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作者：
T. Clifton;D. Gregoris;K. Rosquist;R. Tavakol
我们研究的不均匀性对宇宙演化的影响，通过考虑一系列的宇宙学模型与离散的物质含量。这是使用精确的和完全相对论性的方法来完成的，这些方法利用了时空子流形中及其周围的对称性，而这些子流形本身并不具有连续的全局对称性。这些方法使我们能够跟踪我们的模型在整个历史中的演变，远远超出了以前的可能性。我们发现，虽然一些类空曲线在有限时间内崩溃各向异性奇点，其他保持非奇异永远。由此产生的宇宙学时空图像中，一些行为仍然接近弗里德曼，而其他行为则从根本上偏离。特别是，我们发现，大规模的加速是可能的，没有任何违反的能量条件。
We study the effects of inhomogeneities on the evolution of the Universe, by considering a range of cosmological models with discretized matter content. This is done using exact and fully relativistic methods that exploit the symmetries in and about submanifolds of spacetimes that themselves possess no continuous global symmetries. These methods allow us to follow the evolution of our models throughout their entire history, far beyond what has previously been possible. We find that while some space-like curves collapse to anisotropic singularities in finite time, others remain non-singular forever. The resulting picture is of a cosmological spacetime in which some behaviour remains close to Friedmann-like, while other behaviours deviate radically. In particular, we find that large-scale acceleration is possible without any violation of the energy conditions.