An ultralight bosonic particle of mass around $10^{-22}\, \mathrm{eV}/c^2$ is of special interest as a dark matter candidate, as it both has particle physics motivations, and may give rise to notable differences in the structures on highly non-linear scales due to the manifestation of quantum-physical wave effects on macroscopic scales, which could address a number of contentious small-scale tensions in the standard cosmological model, ΛCDM. Using a spectral technique, we here discuss simulations of such fuzzy dark matter (FDM), including the full non-linear wave dynamics, with a comparatively large dynamic range and for larger box sizes than considered previously. While the impact of suppressed small-scale power in the initial conditions associated with FDM has been studied before, the characteristic FDM dynamics are often neglected; in our simulations, we instead show the impact of the full non-linear dynamics on physical observables. We focus on the evolution of the matter power spectrum, give first results for the FDM halo mass function directly based on full FDM simulations, and discuss the computational challenges associated with the FDM equations. FDM shows a pronounced suppression of power on small scales relative to cold dark matter (CDM), which can be understood as a damping effect due to ‘quantum pressure’. In certain regimes, however, the FDM power can exceed that of CDM, which may be interpreted as a reflection of order-unity density fluctuations occurring in FDM. In the halo mass function, FDM shows a significant abundance reduction below a characteristic mass scale only. This could in principle alleviate the need to invoke very strong feedback processes in small galaxies to reconcile ΛCDM with the observed galaxy luminosity function, but detailed studies that also include baryons will be needed to ultimately judge the viability of FDM.

中文翻译：

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模糊暗物质大体积宇宙学模拟中的结构形成：非线性动力学的影响

一个质量约为 $10^{-22}\, \mathrm{eV}/c^2$ 的超轻玻色子粒子作为暗物质候选者特别受关注，因为它都具有粒子物理动机，并可能产生显着差异由于量子物理波效应在宏观尺度上的表现，在高度非线性尺度上的结构中，这可以解决标准宇宙学模型ΛCDM中许多有争议的小尺度张力。使用光谱技术，我们在这里讨论这种模糊暗物质 (FDM) 的模拟，包括完整的非线性波动力学，具有相对较大的动态范围和比以前考虑的更大的盒子尺寸。虽然之前已经研究过在与 FDM 相关的初始条件下抑制小规模功率的影响，但特征 FDM 动力学往往被忽略；在我们的模拟中，我们反而展示了完全非线性动力学对物理可观测物的影响。我们专注于物质功率谱的演变，直接基于完整的 FDM 模拟给出 FDM 晕质量函数的初步结果，并讨论与 FDM 方程相关的计算挑战。相对于冷暗物质 (CDM)，FDM 在小尺度上显示出明显的功率抑制，这可以理解为“量子压力”引起的阻尼效应。然而，在某些情况下，FDM 功率可能超过 CDM，这可以解释为 FDM 中发生的有序单位密度波动的反映。在晕质量函数中，FDM 仅显示低于特征质量尺度的丰度显着降低。