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.
Gamma-ray Constraints on Dark Matter Annihilation into Charged Particles
暗物质湮灭成为带电粒子必然伴随着伽马射线，通过辐射校正产生。来自末态粒子的内部韧致辐射可以产生硬伽马射线，直到暗物质质量，具有近似与模型无关的光谱。专注于湮灭成电子，我们计算强大的上限上的暗物质自湮灭截面$<σ_A v >_{e^+e^-}$使用伽马射线数据从银河系跨越广泛的能量，$\sim10^{-3} - 10^4$ GeV。我们还计算了其他带电轻子相应的边界。我们保守的假设，天体物理的输入，并证明我们的推导出的界限将得到加强，如果更强的假设，这些输入。在与$e^+e^-$湮灭相伴的终点附近，硬伽马射线的比例仅比直接湮灭为单能伽马射线的情况低$\alt 10^2$的一个因子。因此，$<σ_A v >_{e^+e^-}$上的结合比$<σ_A v >_{γγ}$上的结合弱相同的因子。带电轻子湮灭截面的上限与中微子定义的{ \it总}湮灭截面的上限进行了比较。
