Remarks on Cosmic String Formation during Preheating on Lattice Simulations

TL;DR

This study uses lattice simulations to analyze the formation of global cosmic strings during preheating, revealing that string production is sensitive to the breaking scale and lattice dimensions, with implications for early universe evolution.

Contribution

It demonstrates that two- and three-dimensional lattice results are similar during preheating and highlights the conditions under which cosmic strings form at different energy scales.

Findings

Cosmic strings with breaking scale ~10^{16} GeV are produced over a broad parameter range.

Higher breaking scales (~3×10^{16} GeV) have production dependent on specific parameters.

No significant difference between 2D and 3D lattice results during preheating.

Abstract

We reconsider the formation of (global) cosmic strings during and after preheating by calculating the dynamics of a scalar field on both two- and three- dimensional lattices. We have found that there is little differences between the results in two and three dimensions about the dynamics of fluctuations, at least, during preheating. Practically, it is difficult to determine whether long cosmic strings which may affect the later evolution of the universe could ever be produced from the results of simulations on three-dimensional lattices with smaller box sizes than the horizon. Therefore, using two-dimensional lattices with large box size, we have found that cosmic strings with the breaking scale 0\eta \sim 10^{16} GeV are produced for broad range of parameter space in \eta, while for higher breaking scales (\eta \sim 3\times 10^{16} GeV), their production depends crucially on the value of the breaking scale \eta in our simulations.