Axion Constraints in Non-standard Thermal Histories
There is no direct evidence for radiation domination prior to big-bang nucleosynthesis, and so it is useful to consider how constraints to thermally-produced axions change in non-standard thermal histories. In the low-temperature-reheating scenario, radiation domination begins as late as ~1 MeV, and is preceded by significant entropy generation. Axion abundances are then suppressed, and cosmological limits to axions are significantly loosened. In a kination scenario, a more modest change to axion constraints occurs. Future possible constraints to axions and low-temperature reheating are discussed.
Additional Information© 2009 American Institute of Physics. Issue Date: 8 September 2009. D.G. was supported by the Gordon and Betty Moore Foundation and thanks the organizers of DM08. T.L.S. and M.K. were supported by DoE DE-FG03-92-ER40701 and the Gordon and Betty Moore Foundation.
Published - Grin2009p10928Aip_Conf_Proc.pdf