Evolution of String-Wall Networks and Axionic Domain Wall Problem

Understand

We study the cosmological evolution of domain walls bounded by strings which arise naturally in axion models.

• If we introduce a bias in the potential, walls become metastable and finally disappear.
• We perform two dimensional lattice simulations of domain wall networks and estimate the decay rate of domain walls.
• By using the numerical results, we give a constraint for the bias parameter and the Peccei-Quinn scale.