论文标题
宇宙大规模结构的快速模拟和大量中微子
Fast simulations of cosmic large-scale structure with massive neutrinos
论文作者
论文摘要
精确的宇宙学模拟包括非线性物质聚类以及大量中微子的影响对于测量即将进行的星系调查的中微子质量量表至关重要。通常，使用牛顿模拟，并用大量颗粒对中微子分布进行采样，以击败射击噪声。在这里，我们使用巨大的中微子进行非常有效的模拟，这几乎不需要仅仅是物质模拟的额外成本，此外，不需要中微子的示踪剂颗粒。取而代之的是，我们基于最近开发的牛顿运动方法使用弱场词典，其中牛顿的模拟与线性相对论玻尔兹曼代码配对，以使中微子进化吸收到时间相关的坐标转换中。为此，仅需要在现有的n体代码中进行最小修改，我们已经在$ \ textit {gevolution} $和$ \ textit {gadget-2} $中明确实现了。我们的快速方法将非线性物质功率谱与与最先进的模拟相比，以$ 0.1 \，{\ rm ev} \ leq \ summ_ν\ leq leq 0.3 \，$ ev进行比较。
Accurate cosmological simulations that include the effect of non-linear matter clustering as well as of massive neutrinos are essential for measuring the neutrino mass scale from upcoming galaxy surveys. Typically, Newtonian simulations are employed and the neutrino distribution is sampled with a large number of particles in order to beat down the shot noise. Here we perform very efficient simulations with light massive neutrinos which require virtually no extra cost over matter-only simulations, and furthermore do not require tracer particles for the neutrinos. Instead, we use a weak-field dictionary based on the recently developed Newtonion motion approach, where Newtonian simulations for matter are paired with a linear relativistic Boltzmann code to allow for an absorption of the neutrino evolution into a time-dependent coordinate transformation. For this, only minimal modifications in existing N-body codes are required, which we have explicitly implemented in $\textit{gevolution}$ and $\textit{gadget-2}$. Our fast method determines the non-linear matter power spectrum to permille-level precision when compared against state-of-the-art simulations that have been performed for $0.1\,{\rm eV} \leq \sum m_ν\leq 0.3\,$eV.
