The axion solution to the strong CP problem also provides a natural
dark matter candidate. If the PQ symmetry has ever been restored after
inflation, topological defects of the axion field would have formed and
produced relic axions, whose abundance is in principle calculable. Using
numerical simulations I will present a detailed study of the evolution of
axion strings and the resulting spectrum of axion produced. The features
found are important for a correct estimate of the total DM abundance.
See: arXiv:1806.04677 and https://www.youtube.com/watch?v=DbvM7emtodo
