Title: Sub-MHz Radio Background from Ultralight Dark Photon Dark Matter Show Chinese title

Title: 超轻暗光子暗物质的亚兆赫无线电背景

Abstract: Dark photons are a well-motivated candidate for dark matter, but their detection becomes challenging for ultralight masses with both experimental and astrophysical probes. In this work, we propose a new approach to explore this regime through the dark inverse Compton scattering of ultralight dark photons with cosmic ray electrons and positrons. We show this process generates a potentially observable background radiation that is most prominent at frequencies below MHz. We compute this effect using the latest cosmic ray models and radio absorption maps. Comparing it to observations of the Milky Way's radio spectrum from Explorer 43, Radio Astronomy Explorer 2, and the Parker Solar Probe, we place leading constraints on the kinetic mixing of dark photon dark matter for masses $\lesssim 2 \times 10^{-17} \ \rm eV$. Show Chinese abstract

Abstract: 暗光子是暗物质的一个有说服力的候选者，但它们的探测对于超轻质量而言，在实验和天体物理探针方面都变得具有挑战性。 在这项工作中，我们提出了一种新的方法，通过宇宙射线电子和正电子与超轻暗光子的暗反康普顿散射来探索这一领域。我们展示了这个过程会产生一种可能可观测到的背景辐射，在低于兆赫频率时最为显著。我们利用最新的宇宙射线模型和射电吸收图计算了这种效应。将其与探险者43号、射电天文探索者2号以及帕克太阳探测器观测到的银河系射电频谱进行比较，我们对暗光子暗物质的动力学混合施加了领先的限制，适用于质量为$\lesssim 2 \times 10^{-17} \ \rm eV$的情况。