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arXiv 0905.2774hep-thastro-ph.COgr-qc
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从扭曲的额外维度加速宇宙

Accelerating universe from warped extra dimensions

Ishwaree P Neupane

摘要:

加速宇宙或存在一个小而正的宇宙学常数可能是最紧迫的障碍,也是从引力基本理论(包括弦论)中显著改进四维宇宙学模型的机会。在寻求解决这个问题时,人们自然会想,现实世界是否可以被解释为嵌入在由扭曲几何描述的高维时空中的膨胀的德西特膜。在这种情况下,四维宇宙学常数可以用两个尺度来唯一地确定:一个是与额外维度的大小相关的尺度,另一个是与我们宇宙的膨胀率相关的尺度。在某些具体情况下,这两种尺度是相辅相成的。这个结果在这里证明了一些明确的和完全非奇异的de Sitter空间dS $_4$解决方案的真空爱因斯坦方程在5和10维。

英文摘要:

Accelerating universe or the existence of a small and positive cosmological constant is probably the most pressing obstacle as well as opportunity to significantly improving the models of four-dimensional cosmology from fundamental theories of gravity, including string theory. In seeking to resolve this problem, one naturally wonders if the real world can somehow be interpreted as an inflating de Sitter brane embedded in a higher-dimensional spacetime described by warped geometry. In this scenario, the four-dimensional cosmological constant may be uniquely determined in terms of two length scales: one is a scale associated with the size of extra dimensions and the other is a scale associated with the expansion rate of our universe. In some specific cases, these two scales are complementary to each other. This result is demonstrated here by presenting some explicit and completely non-singular de Sitter space dS$_4$ solutions of vacuum Einstein equations in five and ten dimensions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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