Scaling of cosmic string loops

摘要: We study the spectrum of loops as a part complete network cosmic strings in flat spacetime. After long transient regime, characterized by production small at scale initial conditions, it appears that true scaling regime takes over. In this final characteristic length scales $0.1t$, contrast to earlier simulations which found tiny loops. expect expanding-universe behavior be qualitatively similar. If expectation is correct, then large loop sizes have important cosmological implications. particular, nucleosynthesis bound becomes $G\ensuremath{\mu}\ensuremath{\lesssim}{10}^{\ensuremath{-}7}$, much tighter than obtained from analyses.