http://arxiv.org/abs/2205.07194
We perform a direct search for an isotropic stochastic gravitational-wave background (SGWB) produced by cosmic strings in the Parkes Pulsar Timing Array second data release. We find no evidence for such an SGWB, and therefore place $95\%$ confidence level upper limits on the cosmic string tension, $G\mu$, as a function of the reconnection probability, $p$, which can be less than 1 in the string-theory-inspired models. The upper bound on the cosmic string tension is $G\mu \lesssim 5.1 \times 10^{-10}$ for $p = 1$, which is about five orders of magnitude tighter than the bound derived from the null search of individual gravitational wave burst from cosmic string cusps in the PPTA DR2.
Z. Chen, Y. Wu and Q. Huang
Tue, 17 May 22
3/95
Comments: 7 pages, 2 figures, 1 table