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arXiv · hep-th/0306291

Hyperbolic Space Cosmologies

Chiang-Mei Chen·Pei-Ming Ho·Ishwaree P. Neupane·Nobuyoshi Ohta·John E. Wang
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Abstract

We present a systematic study of accelerating cosmologies obtained from M/string theory compactifications of hyperbolic spaces with time-varying volume. A set of vacuum solutions where the internal space is a product of hyperbolic manifolds is found to give qualitatively the same accelerating four-dimensional FLRW universe behavior as a single hyperbolic space. We also examine the possibility that our universe is a hyperbolic space and provide exact Milne type solutions, as well as intersecting S-brane solutions. When both the usual 4D spacetime and the m-dimensional internal space are hyperbolic, we find eternally accelerating cosmologies for $m\geq 7$, with and without form field backgrounds. In particular, the effective potential for a magnetic field background in the large 3 dimensions is positive definite with a local minimum and thus enhances the eternally accelerating expansion.

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Chiang-Mei Chen, Pei-Ming Ho, Ishwaree P. Neupane, Nobuyoshi Ohta, John E. Wang. 2003-11-09. Hyperbolic Space Cosmologies. https://doi.org/10.1088/1126-6708%2F2003%2F10%2F058

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