# Axion CDM analogous to reheating?

In a paper on Axions Peccei writes:

When the Universe goes through the PQ phase transition at $$T ∼ f_a > > Λ_{QCD}$$ the QCD anomaly is ineffective. As a result, early in the Universe $$< a_{phys} >$$ is arbitrary. Eventually, when the Universe cools down to temperatures of order $$T \sim Λ_{QCD}$$ the axion obtains a mass and $$→ 0$$. The PQ mechanism through which this happens, however, is not an instantaneous process and $$< a_{phys} >$$ oscillates to its final value. These coherent $$p_a = 0$$ axion oscillations contribute to the Universe’s energy density and axions act as cold dark matter.

He denotes by $$a$$ the axion field and $$f_a$$ the spontaneous PQ symmetry breaking energy scale.

Does he mean that in the early universe axions would be generated when the PQ symmetry is broken in a process analogous to reheating in inflation, or am I fully mistaken by this analogy?