Nambu-Goto Dynamics of Field Theory Cosmic String Loops

TL;DR

This study compares cosmic string loop dynamics from field theory simulations with Nambu-Goto predictions, revealing energy loss through massive radiation in high curvature regions and implications for cosmological models.

Contribution

It provides a detailed comparison between field theory simulation results and Nambu-Goto theory, highlighting energy emission mechanisms and their impact on loop evolution.

Findings

Loops follow Nambu-Goto trajectories except at high curvature.

Energy is emitted as massive radiation during high curvature regions.

Loops often annihilate before completing an oscillation.

Abstract

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.