2005/03/31 by E. R. Siegel, J. N. Fry · 1 citation
Physics and Astronomy · #astro-ph #hep-ph
paper · pdf · doi:10.1016/j.physletb.2005.03.013
published as Phys.Lett. B612 (2005) 122-126 · 5 pages, 1 figure, requires autart.cls, to appear in Phys. Lett. B, 1 reference added
arxiv created 2005/04/05 · arxiv updated 2009/12/01
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.