arXiv 1606.055522016-06-17hep-phastro-ph.COhep-ex

排列轴子模型中的拓扑缺陷与纳赫兹引力波

Topological Defects and nano-Hz Gravitational Waves in Aligned Axion Models

Tetsutaro Higaki, Kwang Sik Jeong, Naoya Kitajima, Toyokazu Sekiguchi, Fuminobu Takahashi

备注：: 23 pages, 7 figures
DOI：: 10.1007/JHEP08(2016)044

摘要：

研究了具有多个Peccei-Quinn标量的对齐轴子模型中拓扑缺陷的形成和演化，其中QCD轴子是由衰变常数远小于传统Peccei-Quinn破缺标度的轴子组合实现的.当U（1）对称性自发破缺时，轴子场空间中的排列结构表现为实空间中复杂的弦壁网络。我们发现如果Peccei-Quinn标量的个数大于2，弦壁网络很可能会存在到QCD相变。弦壁系统在QCD相变过程中发生坍缩，产生了大量的纳赫兹量级的引力波。脉冲星定时观测将脉冲星的典型衰变常数限制在O（100）TeV以下，在未来的SKA观测中，这一限制将提高2倍。

英文摘要：

We study the formation and evolution of topological defects in an aligned axion model with multiple Peccei-Quinn scalars, where the QCD axion is realized by a certain combination of the axions with decay constants much smaller than the conventional Peccei-Quinn breaking scale. When the underlying U(1) symmetries are spontaneously broken, the aligned structure in the axion field space exhibits itself as a complicated string-wall network in the real space. We find that the string-wall network likely survives until the QCD phase transition if the number of the Peccei-Quinn scalars is greater than two. The string-wall system collapses during the QCD phase transition, producing a significant amount of gravitational waves in the nano-Hz range at present. The typical decay constant is constrained to be below O(100) TeV by the pulsar timing observations, and the constraint will be improved by a factor of 2 in the future SKA observations.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文