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A Thermal Graviton Background from Extra Dimensions

E. R. Siegel·J. N. Fry
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Abstract

Inflationary cosmology predicts a low-amplitude graviton background across a wide range of frequencies. This Letter shows that if one or more extra dimensions exist, the graviton background may have a thermal spectrum instead, dependent on the fundamental scale of the extra dimensions. The energy density is shown to be significant enough that it can affect nucleosynthesis in a substantial way. The possibility of direct detection of a thermal graviton background using the 21-cm hydrogen line is discussed. Alternative explanations for the creation of a thermal graviton background are also examined.

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E. R. Siegel, J. N. Fry. 2005-04-05. A Thermal Graviton Background from Extra Dimensions. https://doi.org/10.1016/j.physletb.2005.03.013

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