Survival of pq-superstrings in field theory simulations

Understand

We perform large-scale field theoretical simulations in expanding universe to characterize a network of strings that can form composed bound states.

• The network consists of two copies of Abelian Higgs strings (which we label p and q, respectively) coupled via a potential term to give pq bound states.
• The simulations are performed using two different kinds of initial conditions: the first one with a network of p- and q-strings, and the second one with a network of q- and pq-strings.
• This way, we start from two opposite situations: one with no initial pq-strings, and one with a large initial number of pq-strings.