Constraining Axion and ALP Dark Matter from Misalignment during Reheating

Understand

We explore the phenomenology of QCD axion and axion-like particle (ALP) dark matter production via misalignment during inflationary reheating.

• We investigate scenarios involving inflaton oscillating in a generic potential $\sim \phi^n$, considering inflaton decay and annihilation for reheating.
• For low reheating temperatures, the parameter space leading to the correct relic abundance can be enlarged beyond the standard case.
• Depending on the type of inflaton-matter couplings and the value of $n$, we find that certain parts of the extended parameter space are already constrained by ADMX, CAPP, and MUSE experiments.