Scaling properties of cosmic (super)string networks

Abstract

I use a combination of state-of-the-art numerical simulations and analytic modelling to discuss the scaling properties of cosmic defect networks, including superstrings. Particular attention is given to the role of extra degrees of freedom in the evolution of these networks. Compared to the 'plain vanilla' case of Goto-Nambu strings, three such extensions play important but distinct roles in the network dynamics: the presence of charges/currents on the string worldsheet, the existence of junctions, and the possibility of a hierarchy of string tensions. I also comment on insights gained from studying simpler defect networks, including Goto-Nambu strings themselves, domain walls and semilocal strings.

Extending the velocity-dependent one-scale model for domain walls

“…Meanwhile, the latter can be more easily simulated numerically at higher spatial resolution and dynamic range. For this reason, in addition to their intrinsic relevance, domain walls also provide a useful testbed for the evolution of cosmic strings and superstrings [10]. Still, the velocitydependent one-scale model (VOS) for domain walls is currently less developed than its cosmic string counterpart.…”