论文标题
使用自相似性量化宇宙n体仿真中的分辨率
Quantifying resolution in cosmological N-body simulations using self-similarity
论文作者
论文摘要
我们证明，对无尺度模拟中自相似性的测试为量化宇宙N体模拟的小尺度分辨率提供了出色的工具。分析使用算盘中测量的两点相关函数，我们显示观察到的与自相似性的偏差如何揭示获得收敛的时间和距离范围的范围。虽然稳定量表的准确性低于1％，但我们的结果表明，在力较小的长度上，空间分辨率基本上取决于质量分辨率。在以后的时间，融合的较低截止比例会以$ a^{ - 1/2} $（$ a $为比例因素）演变为com comovence comvence comvence comvence comvence comvence comvence comvence comvence in Comovence in Comovence comovence comvence comvence comvence comvence com的较低规模均演变为一致的，即它是由两体碰撞性设定的。我们的结果的必然性是，N体模拟，尤其是在高红移时，包含一个显着的空间范围，在该范围内，聚类似乎相对于时间稳定和力量软化而融合，但实际上并未融合到物理连续性结果。开发的方法可以应用于确定任何聚类统计量的分辨率，并扩展以推断非仿真的分辨率限制。
We demonstrate that testing for self-similarity in scale-free simulations provides an excellent tool to quantify the resolution at small scales of cosmological N-body simulations. Analysing two-point correlation functions measured in simulations using ABACUS, we show how observed deviations from self-similarity reveal the range of time and distance scales in which convergence is obtained. While the well-converged scales show accuracy below 1 percent, our results show that, with a small force softening length, the spatial resolution is essentially determined by the mass resolution. At later times the lower cut-off scale on convergence evolves in comoving units as $a^{-1/2}$ ($a$ being the scale factor), consistent with a hypothesis that it is set by two-body collisionality. A corollary of our results is that N-body simulations, particularly at high red-shift, contain a significant spatial range in which clustering appears converged with respect to the time-stepping and force softening but has not actually converged to the physical continuum result. The method developed can be applied to determine the resolution of any clustering statistic and extended to infer resolution limits for non-scale-free simulations.
