We discuss the possibility of exploring an unbroken U(1) gauge interaction in the dark sector by means of gravitational waves. Dark sector states charged under the dark force can give a macroscopic charge to astronomical bodies. Yet the requirement of having gravitationally bounded stars limits this charge to negligible values if the force has a sizeable strength. Gravitational tests are only possible if the dark force is weaker than gravity. By solving the Einstein-Maxwell field equations, we study in detail an explicit model for dark charge generation and separation in a neutron star. Charged states originate from the decay of neutrons inside the star into three dark fermions; we show that in this model the equation of state is consistent with limits on neutron star masses and tidal deformability. We find that while the dark force can be observed in binary mergers (making them an optimal observational test even though with limited precision), it is Debye screened in binary pulsars (for which more precise data exist). The emitted radiation in the inspiral phase of a binary system is modified and the dark force tested at the level of the uncertainty of the experimental detection. The test covers a region where current limits on deviations from Newton inverse-squared law come from geophysical and laser-ranging observations.

中文翻译：

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带电中子星和暗力比重力弱的观测试验

我们讨论了通过引力波探索暗区中不间断的 U(1) 规范相互作用的可能性。在黑暗力量下充电的暗扇区状态可以给天体带来宏观电荷。然而，如果该力具有相当大的强度，那么拥有受引力限制的恒星的要求会将这种电荷限制为可以忽略不计的值。只有当暗力弱于引力时，引力测试才有可能。通过求解爱因斯坦-麦克斯韦场方程，我们详细研究了中子星中暗电荷产生和分离的显式模型。带电状态源于恒星内部的中子衰变成三个暗费米子；我们表明，在该模型中，状态方程与中子星质量和潮汐变形能力的限制一致。我们发现，虽然可以在双星合并中观察到暗力（即使精度有限，也可以使它们成为最佳的观测测试），但在双脉冲星（存在更精确的数据）中对它进行了德拜筛选。在二元系统的吸气相中发射的辐射被修改，并在实验检测的不确定性水平上测试暗力。该测试覆盖了一个区域，该区域当前对牛顿平方反比定律偏差的限制来自地球物理和激光测距观测。在二元系统的吸气相中发射的辐射被修改，并在实验检测的不确定性水平上测试暗力。该测试覆盖了一个区域，该区域当前对牛顿平方反比定律偏差的限制来自地球物理和激光测距观测。在二元系统的吸气相中发射的辐射被修改，并在实验检测的不确定性水平上测试暗力。该测试覆盖了一个区域，该区域当前对牛顿平方反比定律偏差的限制来自地球物理和激光测距观测。