We propose that the recent observations reported by the different Pulsar Timing Array (PTA) collaborations (i.e.~IPTA, EPTA, PPTA, and NANOGrav) of a common process over several pulsars could correspond to a stochastic gravitational wave background (SGWB) produced by turbulent sources in the early universe, in particular due to the magnetohydrodynamic (MHD) turbulence induced by primordial magnetic fields. I discuss recent results of numerical simulations of MHD turbulence and present an analytical template of the SGWB validated by the simulations. We use this template to constrain the magnetic field parameters using the results reported by the PTA collaborations. Finally, we compare the constraints on the primordial magnetic fields obtained from PTA with those from blazar signals observed by Fermi Large Area Telescope (LAT), from ultra high-energy cosmic rays, and from the cosmic microwave background. We show that a non-helical primordial magnetic field produced at the scale of the quantum chromodynamics phase transition is compatible with such constraints and it could additionally provide with a magnetic field at recombination that would help to alleviate the Hubble tension.
A Realistic Pulsar -- Supermassive Black Hole Timing Model
Peking University（北京大学）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）
CENTRA, Departamento de Física, Instituto Superior Técnico – IST Universidade de Lisboa – UL（里斯本大学高级技术学院物理系中心）；Departamento de Física Fundamental, Universidad de Salamanca（萨拉曼卡大学基础物理系）；Insituto Universitario de Física Fundamental y Matemáticas (IUFFyM), Universidad de Salamanca（萨拉曼卡大学基础物理与数学大学研究所）
Why Gravitational Wave Science Needs Pulsar Timing Arrays And Why Pulsar Timing Arrays Need Both Arecibo and the GBT: A Response to the NSF-AST Portfolio Review from the NANOGrav Collaboration
Searching for gravitational waves from the Crab pulsar - the problem of timing noise
蟹状星云脉冲星（B 0531 +21）是目前已知的最有希望的引力波源之一。蟹状星云相对较大的定时噪声导致其相位演化偏离简单的自旋下降模型。在对蟹状星云脉冲星进行时域搜索时，需要考虑这种影响，以避免搜索效率的严重下降。Jodrell Bank Crab脉冲星星历表的检查，看看它是否可以用于跟踪相位演化的任何引力波信号从脉冲星，我们提出了一种外差的数据，考虑到相位漂移的方法。从电磁和引力观测的定时噪声的比较获得有关脉冲星的物理信息的可能性进行了讨论。最后，脉冲星毛刺所造成的其他问题进行了讨论。
Millisecond and Binary Pulsars as Nature's Frequency Standards. III. Fourier Analysis and Spectral Sensitivity of Timing Observations to Low-Frequency Noise
Pulsar timing array signals induced by black hole binaries in relativistic eccentric orbits
非圆轨道上的单个超大质量黑洞双星可能是快速成熟的脉冲星定时阵列实验的纳赫兹引力波源。我们发展了一种精确有效的方法来计算脉冲星定时阵列信号，由于引力波从吸入相对论偏心轨道的超大质量黑洞双星。我们的方法采用开普勒型参数解模型的第三后牛顿精确进动偏心轨道，而一个新的半解析处方提供了模型的四极阶引力波发射的影响。这些输入导致一个半解析的处方来模拟这样的信号，引起的非自旋黑洞二进制沿任意偏心率轨道螺旋。此外，我们提供了一个完整的分析处方模型脉冲星定时阵列信号从黑洞二进制沿适度偏心轨道吸气，Boetzelet等人的影响。[Phys. Rev. D 96，044011（2017）]。这些方法正在被纳入企业和TEMPO 2搜索脉冲星定时阵列数据集中存在这样的二进制文件。
Non-Gaussian timing residual skewness in pulsar timing arrays
Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Leibnitz Universität Hannover（马克斯·普朗克引力物理研究所（爱因斯坦研究所），莱布尼茨汉诺威大学）；Department of Physics, National Central University（国立中央大学物理系）；Institute of Physics, Academia Sinica（台湾中央研究院物理研究所）；Institute of Astronomy and Astrophysics, Academia Sinica（台湾中央研究院天文及天文物理研究所）
Detecting Chiral Gravitational Wave Background with a Dipole Pulsar Timing Array
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences（中国科学院大学杭州高等研究院）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Institute of Fundamental Physics and Quantum Technology, Ningbo University（宁波大学基础物理与量子技术研究所）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo（东京大学宇宙木理论研究所）；Asia Pacific Center for Theoretical Physics（亚太理论物理中心）；Leung Center for Cosmology and Particle Astrophysics, National Taiwan University（台湾大学梁氏宇宙学与粒子天体物理学研究中心）；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）
