摘要
Recently,pulsar timing array(PTA)experiments have provided compelling evidence for the existence of the nanohertz stochastic gravitational wave background(SGWB).In this work,we demonstrated that cosmic string loops generated from cosmic global strings offer a viable explanation for the observed nanohertz SGWB data,requiring a cosmic string tension parameter of log(Gμ)~-12 and a loop number density of log N~4.Additionally,we revisited the impact of cosmic string loops on the abundance of massive galaxies at high redshifts.However,our analysis revealed challenges in identifying a consistent parameter space that can concurrently explain both the SGWB data and observations from the James Webb Space Telescope.This indicates the necessity for either extending the existing model employed in this research or acknowledging distinct physical origins for these two phenomena.
基金
supported by the National Key Research and Development Program of China(Grant No.2022YFF0503304)
the National Natural Science Foundation of China(Grant No.11921003)
the New Cornerstone Science Foundation through the XPLORER PRIZE
the Chinese Academy of Sciences
the Entrepreneurship and Innovation Program of Jiangsu Province。