Stability of Axion Dark Matter-Photon Conversion

Understand

It is known that a coherently oscillating axion field is a candidate of the dark matter.

• In the presence of the oscillating axion, the photon can be resonantly produced through the parametric amplification.
• In the universe, there also exist cosmological magnetic fields which are coherent electromagnetic fields.
• In the presence of magnetic fields, an axion can be converted into a photon, and vice versa.