The ability of Lisa, Taiji, and their networks to detect the stochastic gravitational wave background generated by Cosmic Strings

TL;DR

This paper evaluates the detection capabilities of Lisa, Taiji, and their network for stochastic gravitational wave backgrounds from cosmic strings, showing the network's superior sensitivity and potential to provide evidence for cosmic string signals.

Contribution

It introduces a comparative analysis of space-based detectors' ability to detect cosmic string-generated SGWB signals, highlighting the enhanced performance of the Lisa-Taiji network.

Findings

Lisa-Taiji network outperforms individual detectors in detecting cosmic string signals.

The network can estimate cosmic string tension with high precision at low Gμ values.

Strong evidence for cosmic string signals can be achieved at Gμ around 10^{-16}.

Abstract

The cosmic string contributes to our understanding and revelation of the fundamental structure and evolutionary patterns of the universe, unifying our knowledge of the cosmos and unveiling new physical laws and phenomena. Therefore, we anticipate the detection of Stochastic Gravitational Wave Background (SGWB) signals generated by cosmic strings in space-based detectors. We have analyzed the detection capabilities of individual space-based detectors, Lisa and Taiji, as well as the joint space-based detector network, Lisa-Taiji, for SGWB signals produced by cosmic strings, taking into account other astronomical noise sources. The results indicate that the Lisa-Taiji network exhibits superior capabilities in detecting SGWB signals generated by cosmic strings and can provide strong evidence. The Lisa-Taiji network can achieve an uncertainty estimation of $\Delta G\mu/G\mu<0.5$ for cosmic string tension $G\mu\sim4\times10^{-17}$, and can provide evidence for the presence of SGWB signals generated by cosmic strings at $G\mu\sim10^{-17}$, and strong evidence at $G\mu\sim10^{-16}$. Even in the presence of only SGWB signals, it can achieve a relative uncertainty of $\Delta G\mu/G\mu<0.5$ for cosmic string tension $G\mu<10^{-18}$, and provide strong evidence at $G\mu\sim10^{-17}$.