  We consider the production of axion dark matter through the misalignment
mechanism in the context of a nonstandard cosmological history involving early
matter domination by a scalar field with a time-dependent decay rate. In cases
where the temperature of the Universe experiences a temporary period of
increase, Hubble friction can be restored in the evolution of the axion field,
resulting in the possibility of up to three "crossings" of the axion mass and
the Hubble expansion rate. This has the effect of dynamically resetting the
misalignment mechanism to a new initial state for a second distinct phase of
oscillation. The resultant axion mass required for the present dark matter
relic density is never bigger than the standard-history window and can be
smaller by more than three orders of magnitude, which can be probed by upcoming
experiments such as ABRACADABRA, KLASH, ADMX, MADMAX, and ORGAN, targeting the
axion-photon coupling. This highlights the possibility of exploring the
cosmological history prior to Big Bang Nucleosynthesis through searches for
axion dark matter beyond the standard window.
