QCD axion dark matter and the cosmic dipole anomaly

Abstract

There is growing evidence that the cosmic dipole measured from the distant galaxy number-count is not consistent with that of CMB. We find that the QCD axion, a hypothetical particle originating from the spontaneous breaking of the Peccei-Quinn symmetry, could explain this dipole anomaly if it constitutes the dark matter of our universe. This model requires that the Hubble parameter during inflation should be lower than $10^{7}$ GeV which indicates low scale inflation.Comment: 6 pages, 2 figures, more references adde