Emission of Photons and Relativistic Axions from Axion Stars

Understand

The number of nonrelativistic axions can be changed by inelastic reactions that produce photons or relativistic axions.

• Any odd number of axions can annihilate into two photons.
• Any even number of nonrelativistic axions can scatter into two relativistic axions.
• We calculate the rate at which axions are lost from axion stars from these inelastic reactions.