AI 中文总结
研究标准模型复单态扩展模型中一阶相变爆燃阶段的流体动力学对赝标量暗物质丰度的影响，发现流体动力学再加热可提升已退耦暗物质的丰度，且数值与解析方法在轻质量情形偏差较小。
AI 中文摘要
过滤暗物质为一阶相变过程中产生大质量暗物质粒子提供了一种机制，其产生的丰度可被等离子体流体动力学修正。我们在标准模型的复单态扩展模型中研究该效应，聚焦于爆燃 regime（爆燃阶段）。采用解析和数值两种方法计算熵归一化暗物质丰度$Y_\text{\textbackslash chi}$。随着暗物质质量增加，我们识别出成核前丰度演化的三种模式，涵盖热平衡、热抑制及 freeze-out（退耦）。对于$\text{\textbackslash xi}_w=0.01$，当$m_\text{\textbackslash chi}=1.78$、$2.30$、$5.03\text{ TeV}$时，激波加热使$Y_\text{\textbackslash chi}$分别提升约4.3倍、5.8倍、32倍。对于前两个较轻质量，数值与解析结果偏差在5%以内，计入流体动力学效应后偏差降至约1%或更小；最重质量情形需数值处理，因其成核前已发生暗物质退耦。我们的结果表明，即使暗物质在相变前已退耦，流体动力学 reheating（再加热）仍可提升$Y_\text{\textbackslash chi}$，该情形下$Y_\text{\textbackslash chi}$由成核前建立的暗物质丰度及泡壁处的流体动力学过滤共同决定。
英文摘要
Filtered dark matter provides a mechanism for producing massive dark matter particles during a first order phase transition. The resulting abundance can be modified by plasma hydrodynamics. We investigate this effect in a complex singlet extension of the Standard Model, focusing on the deflagration regime. The entropy normalized dark matter abundance $Y_χ$ is calculated using both analytic and numerical methods. As the dark matter mass increases, we identify three patterns of abundance evolution before nucleation, ranging from thermal equilibrium to thermal suppression and freeze-out. For $ξ_w=0.01$, we find that shock heating increases $Y_χ$ by factors of approximately $4.3$, $5.8$, and $32$ for $m_χ=1.78$, $2.30$, and $5.03~\mathrm{TeV}$, respectively. For the two lighter masses, the numerical and analytic results agree within $5\%$, and the difference is reduced to about $1\%$ or less when hydrodynamic effects are included. The heaviest case requires a numerical treatment because dark matter freeze-out before nucleation. Our results show that hydrodynamic reheating can enhance $Y_χ$ even when dark matter has already frozen out before the phase transition. In this regime, $Y_χ$ is determined by the dark matter abundance established before nucleation and hydrodynamic filtering at the bubble wall.
Comments22 pages, 3 figures,
