利用MeerKAT脉冲星计时阵列和平方公里阵列脉冲星计时阵列预测探测引力子质量

中文摘要 AI 辅助

我们利用MeerKAT脉冲星计时阵列（MPTA）4.5年的数据发布结果对引力子质量进行了限制，并对即将到来的平方公里阵列脉冲星计时阵列（SKA-PTA）进行了预测。通过对大质量引力子的修正色散关系和相应的张量相关函数进行建模，我们在三种噪声配置（DATA、ER、ALT）下对角度相关测量进行了贝叶斯推断。我们得到的引力子质量的90%可信上限为：在DATA配置下\(m_g < 2.10 \times 10^{-23}\,\mathrm{eV}/c^{2}\)，在ER配置下\(m_g < 2.58 \times 10^{-23}\,\mathrm{eV}/c^{2}\)，在ALT配置下\(m_g < 2.25 \times 10^{-23}\,\mathrm{eV}/c^{2}\)。包含单极和偶极贡献并没有显著改变这些界限，证实了这些限制是由四极张量相关性驱动的。所有结果与广义相对论完全一致。对于SKA-PTA，我们预测在10年观测基线时灵敏度可达\(m_g \sim 10^{-24}\,\mathrm{eV}/c^{2}\)，在50年观测基线时可达\(m_g \sim 10^{-25}\,\mathrm{eV}/c^{2}\)，比当前限制有数量级的提升。这项工作展示了当前和未来PTA观测在测试纳赫兹频段引力基本方面的能力。

英文摘要

We present constraints on the graviton mass using the 4.5-year data release from the MeerKAT Pulsar Timing Array (MPTA) and provide forecasts for the upcoming Square Kilometre Array PTA (SKA--PTA). By modeling the modified dispersion relation and the corresponding tensor correlation function for massive gravitons, we perform Bayesian inference on the angular-correlation measurements under three noise configurations (DATA, ER, ALT). Our 90\% credible upper limits on the graviton mass are $m_g < 2.10 \times 10^{-23}\,\mathrm{eV}/c^{2}$ (DATA), $m_g < 2.58 \times 10^{-23}\,\mathrm{eV}/c^{2}$ (ER), and $m_g < 2.25 \times 10^{-23}\,\mathrm{eV}/c^{2}$ (ALT). Including monopolar and dipolar contributions does not significantly alter these bounds, confirming that the constraints are driven by the quadrupolar tensor correlation. All results remain fully consistent with general relativity. For SKA--PTA, we forecast sensitivities down to $m_g \sim 10^{-24}\,\mathrm{eV}/c^{2}$ with a 10-year observing baseline and $m_g \sim 10^{-25}\,\mathrm{eV}/c^{2}$ with a 50-year observing baseline, representing order-of-magnitude improvements over current limits. This work demonstrates the power of current and future PTA observations to test fundamental aspects of gravity in the nanohertz band.

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12 pages, 4 figures