AI 中文总结
该研究构建了含排斥性自相互作用的超轻暗物质模型，从特定五维作用量出发，经紧致化得到暗物质标量场。单费米子情形为吸引作用，两个费米子可产生排斥作用。检验了模型自洽性，发现不同质量下暗物质表现不同，参数范围广。
AI 中文摘要
我们从一个仅包含一个\(U(1)\)规范场以及几个大质量带电自由费米子的五维作用量出发，构建了一个具有排斥性自相互作用的超轻暗物质模型。在紧致化到四维后，暗物质标量场对应于规范场的第五分量。单费米子情形仅导致吸引性自相互作用，但两个费米子由于第五维的Scherk - Schwarz扭结能产生排斥性自相互作用。我们检验了该模型从暴胀阶段到当前时间的观测和理论自洽性，发现允许很大范围的模型参数。标量质量低于\(10^{-12}\)eV时自相互作用可忽略，模型表现为模糊暗物质；质量更高时，排斥性自相互作用主导天体物理尺寸孤子的形成，更大尺寸需要在模糊暗物质区域有大的初始失准或小质量。
英文摘要
We build an ultralight dark matter model with repulsive self-interactions, starting from a 5D action that only includes a $U(1)$ gauge field and several massive and charged free fermions. The dark matter scalar field corresponds to the fifth component of the gauge field, after compactification to 4D. Although the single-fermion case only leads to attractive self-interactions, two fermions can already give rise to repulsive self-interactions, thanks to a Scherk-Schwarz twist around the fifth dimension. We check the observational and theoretical self-consistency of this scenario, from the inflation stage to the current time. We find that large ranges of model parameters are allowed. For scalar masses below $10^{-12}$ eV the self-interactions are negligible and the model behaves as fuzzy dark matter. For higher masses the repulsive self-interactions govern the formation of solitons of astrophysical size. Larger sizes require a large initial misalignment or small masses in the fuzzy dark matter regime.
Comments20 pages
