Imprints of an early matter-dominated era arising from dark matter dilution mechanism on cosmic string dynamics and gravitational wave signatures

TL;DR

This paper explores how an early matter-dominated era caused by dark matter dilution affects cosmic string behavior and gravitational wave signals, predicting distinctive high-frequency spectrum suppression detectable by future experiments.

Contribution

It introduces a detailed numerical analysis of the impact of an early matter-dominated era from dark matter dilution on cosmic string dynamics and gravitational wave signatures within a minimal left-right symmetric model.

Findings

Suppression of high-frequency gravitational wave spectrum

Distinct signatures for future gravitational wave detectors

Altered cosmic string loop density due to early matter domination

Abstract

We investigate the influence of an early matter-dominated era in cosmic history on the dynamics of cosmic strings and the resulting stochastic gravitational waves. Specifically, we examine the case where this era originates from the dark matter dilution mechanism within the framework of the minimal left-right symmetric model. By numerically solving the Boltzmann equations governing the energy densities of the relevant components, we meticulously analyze the modifications to the cosmological scale factor, the number density of cosmic string loops, and the gravitational wave spectrum. Our results reveal that the early matter-dominated era causes a characteristic suppression in the high-frequency regime of the gravitational wave spectrum, providing distinct and testable signatures for future ground-based interferometer experiments.