Kelly Kevin J, Sen Manibrata, Zhang Yue
Theory Department, Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
Department of Physics, University of California Berkeley, Berkeley, California 94720, USA.
Phys Rev Lett. 2021 Jul 23;127(4):041101. doi: 10.1103/PhysRevLett.127.041101.
The self-interacting neutrino hypothesis is well motivated for addressing the tension between the origin of sterile neutrino dark matter and indirect detection constraints. It can also result in a number of testable signals from the laboratories to the cosmos. We show that, in a broad class of models, where the sterile neutrino dark matter relic density is generated by a light neutrinophilic mediator, there must be a lower bound on the amount of extra radiation in early Universe, in particular, ΔN_{eff}>0.12 at the cosmic microwave background (CMB) epoch. This lower bound will be further strengthened with an improved x-ray search at the Athena observatory. Such an intimate relationship will be unambiguously tested by the upcoming CMB Stage 4 project.
自相互作用中微子假说对于解决 sterile 中微子暗物质起源与间接探测限制之间的矛盾具有充分的动机。它还能产生一系列从实验室到宇宙的可测试信号。我们表明，在一大类模型中，其中 sterile 中微子暗物质遗迹密度由一个轻的亲中微子媒介子产生，早期宇宙中额外辐射量必定存在一个下限，特别是在宇宙微波背景（CMB）时期，ΔNₑբբ > 0.12。随着雅典娜天文台对 X 射线搜索的改进，这个下限将进一步加强。即将到来的 CMB 第四阶段项目将明确检验这种紧密关系。
