论文标题
搜索宇宙弦诱导的随机重力波背景，并带有Parkes Pulsar Piming Array
Searching for cosmic string induced stochastic gravitational wave background with the Parkes Pulsar Timing Array
论文作者
论文摘要
我们在15年内使用Parkes Pulsar定时阵列数据搜索从宇宙字符串发出的随机引力背景。虽然我们发现几个脉冲星定时阵列实验揭示的普通幂次过量可能是由宇宙弦的引力背景来解释的，但缺乏特征性的地狱性相关性尚未确定其物理起源。因此，对宇宙字符串模型参数的约束是通过保守的假设得出的，即普通幂律过量是由于背景未知而引起的。考虑了两个具有不同循环分布功能的代表性宇宙弦模型。我们在无量纲字符串张力参数上获得约束，$gμ<10^{ - 11} \ sim10^{ - 10} $，比高频Ligo-virgo实验获得的一个模型更严格，而一个模型更严格，而另一个模型则更严格。结果提供了测试大统一理论的机会，以$ u（1）$的自发对称破坏量表为$ 10^{16} $ GEV的两到三个数量级。因此，Pulsar的时序阵列实验与Ligo-Virgo实验相当互补，以探测早期宇宙中宇宙字符串和超出标准模型物理的基础。
We search for stochastic gravitational wave background emitted from cosmic strings using the Parkes Pulsar Timing Array data over 15 years. While we find that the common power-law excess revealed by several pulsar timing array experiments might be accounted for by the gravitational wave background from cosmic strings, the lack of the characteristic Hellings-Downs correlation cannot establish its physical origin yet. The constraints on the cosmic string model parameters are thus derived with conservative assumption that the common power-law excess is due to unknown background. Two representative cosmic string models with different loop distribution functions are considered. We obtain constraints on the dimensionless string tension parameter $Gμ<10^{-11}\sim10^{-10}$, which is more stringent by two orders of magnitude than that obtained by the high-frequency LIGO-Virgo experiment for one model, and less stringent for the other. The results provide the chance to test the Grand unified theories, with the spontaneous symmetry breaking scale of $U(1)$ being two-to-three orders of magnitude below $10^{16}$ GeV. The pulsar timing array experiments are thus quite complementary to the LIGO-Virgo experiment in probing the cosmic strings and the underlying beyond standard model physics in the early Universe.
