Dynamics of Long-lived Axion Domain Walls and Its Cosmological Implications

Understand

We perform an updated analysis on a long-lived axion domain wall (DW) network.

• By simulating the axion field on a 3D lattice and fitting an analytical model for the DW evolution, we identify the leading energy loss mechanisms of the DWs and compute the spectrum of axions emitted from the network.
• The contribution from the DWs to axion dark matter (DM) density is derived, with viable parameter space given.
• The application to both QCD axions and general axion-like particles (ALPs) are considered.