Physics
Scientific paper
Jan 1992
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992phlb..275..279l&link_type=abstract
Physics Letters B, Volume 275, Issue 3-4, p. 279-283.
Physics
27
Scientific paper
In the scenario where the temperature in the early universe is high enough to restore the Peccei-Quinn symmetry, previous estimates of the axion mass density are reconsidered. The axion contribution to the density parameter is of the form Ωa=K(fa/1012 GeV)1.2 where fa/sqrt(2) is the vacuum value of the magnitude of the Peccei-Quinn field. If axions radiated by strings are ignored, or if they have a flat spectrum as advocated by Harari and Sikivie, K~kγ7/6, where γ-1<1 is the string spacing in Hubble units and k≅1-10. If their spectrum is peaked at frequency γ/t as advocated by Davis, K~10kγ7/6. If γ~1, the first estimate is in essential agreement with earlier ones but the second is a factor of 7 smaller, which widens the allowed window for fa. These estimates include only the axions coming from oscillations of the axion field between the walls. In addition there are axions radiated by the walls, whose relative contribution to K is of order r3/2 in the first case and 0.1r3/2 in the second case, r being the time of wall annihilation divided by the time of wall formation. It could dominate, and close the axion window, if the walls survive for many Hubble times.
No associations
LandOfFree
Estimates of the cosmological axion density does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Estimates of the cosmological axion density, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Estimates of the cosmological axion density will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-940226