Strong constraint on large extra dimensions from cosmology
Strong constraint on large extra dimensions from cosmology
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DOI：
10.1103/physrevd.64.023515
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发表时间：
2001-02
影响因子：
5
通讯作者：
S. Hannestad
中科院分区：
文献类型：
--
作者：
S. Hannestad
我们研究了宇宙学对可能的大额外维度的数量和半径的限制。如果这样的维度存在，那么在早期宇宙的高温下会大量产生卡鲁扎-克莱因（KK）模，并可能导致不可接受的宇宙学效应。我们表明，在再加热过程中，大量的KK模式产生。这些模式不会被再加热过程中的熵产生完全稀释，因为它们是非相对论性产生的。这意味着在再加热期间产生的模式可以容易地成为主导分量。例如，对于两个额外的维度，仅考虑热产生的KK模式，其半径的界限为$Rl~1.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4} \mathrm{mm}。如果再加热过程中产生的模式也被考虑在内，则边界被加强到$Rl~2.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5} \mathrm{mm}。这个界限比所有其他已知的天体物理学或实验室极限都要强。
We study cosmological constraints on the number and radii of possible large extra dimensions. If such dimensions exist, Kaluza-Klein (KK) modes are copiously produced at high temperatures in the early universe, and can potentially lead to unacceptable cosmological effects. We show that during reheating, large numbers of KK modes are produced. These modes are not diluted completely by the entropy production during reheating because they are produced nonrelativistically. This means that the modes produced during reheating can easily be the dominant component. For instance, for two extra dimensions the bound on their radii from considering only the thermally produced KK modes is $Rl~1.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4} \mathrm{mm}.$ If the modes produced during reheating are also accounted for, the bound is strengthened to $Rl~2.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5} \mathrm{mm}.$ This bound is stronger than all other known astrophysical or laboratory limits.