论文标题
汤匙还是滑梯？在大量中微子存在下的非线性物质功率谱
Spoon or slide? The non-linear matter power spectrum in the presence of massive neutrinos
论文作者
论文摘要
大规模中微子宇宙学的数值模拟始终在宇宙学模型的非线性物质功率谱比中找到类似勺子的特征，而宇宙学模型仅在中微子质量分数f_n中有所不同。通常，该比率接近低波数K的统一性，在k〜1 h/mpc时降低约10 f_n，并在大k处再次出现。使用大规模结构的光环模型，我们表明此勺子特征源于从两峰的功率谱向单局部功率谱的过渡。前者对f_n的敏感性随着k而上升，而后者的敏感性则随着k而降低。对于光环质量函数和光晕密度曲线的不同选择，这种勺子特征的存在是可靠的，并且不需要晕模型中的任何参数调整。我们证明，标准的晕圈模型计算已经能够预测该勺子的深度，宽度和位置，以及具有出色精度的红移Z的演化。使用非线性扰动输入可以进一步改善z> = 1的预测。
Numerical simulations of massive neutrino cosmologies consistently find a spoon-like feature in the non-linear matter power spectrum ratios of cosmological models that differ only in the neutrino mass fraction f_N. Typically, the ratio approaches unity at low wave numbers k, decreases by ~ 10 f_N at k ~ 1 h/Mpc, and turns up again at large k. Using the halo model of large-scale structure, we show that this spoon feature originates in the transition from the two-halo power spectrum to the one-halo power spectrum. The former's sensitivity to f_N rises with k, while that of the latter decreases with k. The presence of this spoon feature is robust with respect to different choices of the halo mass function and the halo density profile, and does not require any parameter tuning within the halo model. We demonstrate that a standard halo model calculation is already able to predict the depth, width, and position of this spoon as well as its evolution with redshift z with remarkable accuracy. Predictions at z >= 1 can be further improved using non-linear perturbative inputs.
