Stretching and Kibble scaling regimes for Hubble-damped defect networks
  The cosmological evolution of topological defect networks can broadly be
divided into two stages. At early times they are friction-dominated due to
particle scattering and therefore non-relativistic, and may either be
conformally stretched or evolve in the Kibble regime. At late times they are
relativistic and evolve in the well known linear scaling regime. In this work
we show that a sufficiently large Hubble damping (that is a sufficiently fast
expansion rate) leads to a linear scaling regime where the network is
non-relativistic. This is therefore another realization of a Kibble scaling
regime, and also has a conformal stretching regime counterpart which we
characterize for the first time. We describe these regimes using analytic
arguments in the context of the velocity-dependent one-scale model, and we
confirm them using high-resolution $4096^3$ field theory simulations of domain
wall networks. We also use these simulations to improve the calibration of this
analytic model for the case of domain walls.
