Nambu-Goto dynamics of field theory cosmic string loops

We perform a detailed comparison of the dynamics of cosmic string loops obtained in cosmological field theory simulations with their expected motion according to the Nambu-Goto action. We demonstrate that these loops follow the trajectories predicted within the NG effective theory except in regions of high curvature where energy is emitted from the loop in the form of massive radiation. This energy loss continues for all the loops studied in this simulation until they self-intersect or become small enough that they annihilate and disappear well before they complete a single oscillation. We comment on the relevance of this investigation to the interpretation of the results from cosmological field theory simulations as well as their extrapolation to a cosmological context.

Automated summary

We compare the dynamics of cosmic string loops obtained in cosmological field theory simulations with the expected motion according to the Nambu-Goto action. It is found that these loops generally follow the trajectories predicted within the NG effective theory, except in regions of high curvature where energy is emitted from the loop in the form of massive radiation. This energy loss continues until the loops self-intersect or disappear before completing a single oscillation. The findings are important for interpreting the results from cosmological field theory simulations and their extrapolation to a cosmological context.