Predictions for Axion Couplings from ALP Cogenesis
  Adding an axion-like particle (ALP) to the Standard Model, with a field
velocity in the early universe, simultaneously explains the observed baryon and
dark matter densities. This requires one or more couplings between the ALP and
photons, nucleons, and/or electrons that are predicted as functions of the ALP
mass. These predictions arise because the ratio of dark matter to baryon
densities is independent of the ALP field velocity, allowing a correlation
between the ALP mass, $m_a$, and decay constant, $f_a$. The predicted couplings
are orders of magnitude larger than those for the QCD axion and for dark matter
from the conventional ALP misalignment mechanism. As a result, this scheme, ALP
cogenesis, is within reach of future experimental ALP searches from the lab and
stellar objects, and for dark matter.
