Data: Nonlinear Matter Power Spectrum from relativistic N-body Simulations: ΛsCDM versus ΛCDM

Matter power spectra presented in the associated paper are obtained from the datasets separately generated from N-body simulations with the relativistic code <em>gevolution </em>[1], and from calculations with the linear Boltzmann code CLASS [2], for matching cosmological best-fit parameters and background cosmologies. Regarding the latter element, we study two cases that are the concordance Lambda-Cold Dark Matter (ΛCDM) model and a late-time modification with a sign-switching vacuum sector (ΛsCDM), and for each model there are two best-fit parameter sets, derived from a <em>Planck</em>-only and a combined "full" dataset. 

P(k) (power spectra) outputs from gevolution are computed at the four redshifts z=15, 2, 1, 0 for the density contrasts of total matter (CDM, baryons, and massive neutrinos) as well as CDM-baryons (cb)-only. A detailed explanation of how the matter sector is handled in simulations is available in the main paper. All runs are carried out in boxes of L=2080 Mpc/h with 0.5 h/Mpc resolution.

Power spectra based on CLASS outputs are obtained from the transfer functions of CDM and baryons, and the respective background densities at z=15, 2, 1, 0. CLASS dataset for the latter is shown only up to z=100.

CDM-baryon P(k) outputs with nonlinear corrections from CLASS implementation of HMcode [3] at z=2,1, and 0 are also included in the published data, and have been used in the plots presented in the Appendix of the related manuscript. 

1. J. Adamek, D. Daverio, R. Durrer, and M. Kunz, gevolution: a cosmological N-body code based on General Relativity, JCAP 07, 053. arXiv:1604.06065 [astro-ph.CO].

2. D. Blas, J. Lesgourgues, and T. Tram, The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes, JCAP 07, 034. arXiv:1104.2933 [astro-ph.CO].

3. A. J. Mead, C. Heymans, L. Lombriser, J. A. Peacock, O. I. Steele, and H. A. Winther, Accurate halo-model matter power spectra with dark energy, massive neutrinos and modified gravitational forces, Mon. Not. Roy. Astron. Soc. 459, 1468 (2016). arXiv:1602.02154 [astro-ph.CO].

关联论文中呈现的物质功率谱，分别源自采用相对论性代码gevolution[1]完成的N体模拟生成数据集，以及采用线性玻尔兹曼代码CLASS[2]的计算结果，二者均采用匹配的宇宙学最优拟合参数与背景宇宙学模型。针对背景宇宙学模型，本研究设置了两种情形：一致性Λ冷暗物质（Lambda-Cold Dark Matter, ΛCDM）模型，以及带有符号翻转真空区的晚期修正模型（ΛsCDM）；针对每一种模型，均包含两组最优拟合参数集，分别仅基于普朗克（Planck）卫星数据与联合“全”数据集推导得到。

由gevolution生成的P(k)（功率谱）输出，针对总物质（冷暗物质、重子与大质量中微子）以及仅冷暗物质-重子（cb）的密度对比度，在红移z=15、2、1、0四个红移处完成计算。关于模拟中物质组分的具体处理方式，详见主论文。所有模拟均在边长L=2080 Mpc/h的盒子中开展，空间分辨率为0.5 h/Mpc。

基于CLASS输出结果得到的功率谱，由冷暗物质与重子的传递函数，以及各红移z=15、2、1、0处对应的背景密度计算所得。本次公开的CLASS数据集仅展示至红移z=100。

本次公开的数据中还包含了由CLASS结合HMcode[3]实现的非线性修正得到的冷暗物质-重子P(k)输出，对应红移为z=2、1与0，该结果已用于相关论文附录中的绘图。

1. J. Adamek、D. Daverio、R. Durrer与M. Kunz，《gevolution：一款基于广义相对论的宇宙学N体代码》，JCAP 07, 053. arXiv:1604.06065 [astro-ph.CO]。
2. D. Blas、J. Lesgourgues与T. Tram，《宇宙线性各向异性求解系统（CLASS）II：近似方案》，JCAP 07, 034. arXiv:1104.2933 [astro-ph.CO]。
3. A. J. Mead、C. Heymans、L. Lombriser、J. A. Peacock、O. I. Steele与H. A. Winther，《包含暗能量、大质量中微子与修正引力的高精度晕模型物质功率谱》，Mon. Not. Roy. Astron. Soc. 459, 1468 (2016). arXiv:1602.02154 [astro-ph.CO]。