Perex
The study of domain walls and topological defects has a rich history in cosmology, and they provide a wide range of novel phenomenology to test experimentally. The motivations under which they have been studied include seeding the initial overdensities for structure formation, driving inflation, seeding a stochastic gravitational wave background, and providing the skeleton for the formation of larger structures than expected in the standard model. They can also be linked to the resolution of some of the late-time cosmological tensions. Their nonlinear and dynamical nature motivates numerical studies, which are still challenged by large dynamical ranges. In this talk I will present results from our implementation of late-time topological defects in the relativistic and massively parallelised N-body code gevolution. I give some details on the domain wall dynamics and gravitational wave emission. I will present some considerations on their application towards accounting for the effect of late-time cosmic acceleration, and comment on other models applying nonlinearities that I am currently investigating.