轴子失准景观中的遗忘现象
Amnesia in the Axion Misalignment Landscape
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中文总结 AI 辅助
该研究通过格点模拟探究暴胀前轴子失准景观的演化，发现meV质量范围存在敏感的“峰顶着陆”解，强自相互作用可使不同早期轴子历史产生相似晚期结构。
中文摘要 AI 辅助
暴胀前轴子宇宙学允许初始速度和角度的宽泛范围，由此产生失准历史的景观，其非线性演化结果与小尺度结构仍不确定。我们采用格点模拟方法，追踪QCD轴子在动力学失准场景中，经历QCD渡越进入非相对论 regime，直至物质-辐射相等的全过程。在meV质量范围内，该景观包含一系列对初始角度和速度均敏感的“峰顶着陆”解。非线性碎裂会减少共动轴子数量，并改变失准历史与当前遗迹丰度的关联。对于足够大的轴子质量，强自相互作用会将小尺度谱推向暴胀后轴子的吸引子，因此不同的早期历史可导致相似的晚期结构。
英文摘要
Pre-inflationary axion cosmologies admit a broad range of initial velocities and angles that generate a landscape of misalignment histories, whose nonlinear fate and small-scale structure remain uncertain. We use lattice simulations to follow the QCD axion in the kinetic misalignment scenario through the QCD crossover into the non-relativistic regime, towards matter-radiation equality. In the meV mass range, this landscape contains a continuum of ''summit-landing" solutions sensitive to both the initial angle and velocity. Nonlinear fragmentation reduces the comoving axion number and modifies the relation between the misalignment history and present relic abundance. For sufficiently large axion masses, strong self-interactions drive the small-scale spectrum towards the attractor found for post-inflationary axions, so that distinct early histories can lead to similar late-time structures.
