论文标题
混合BARYON-CDM模拟的高阶初始条件
Higher-order initial conditions for mixed baryon-CDM simulations
论文作者
论文摘要
我们提出了一种新的方法来生成高阶初始条件（IC），以考虑到重子和暗物质的明显演变。我们专注于基于无碰撞N体模拟以及完整的流体动力欧拉和拉格朗日模拟的数值实现及其性能的验证。我们以各种方式改进了以前的方法，这些方法仅限于一阶拉格朗日扰动理论（LPT）。 Specifically, we (1) generalize nth-order LPT to multi-fluid systems, allowing 2LPT or 3LPT ICs for two-fluid simulations, (2) employ a novel propagator perturbation theory to set up ICs for Eulerian codes that are fully consistent with 1LPT or 2LPT, (3) demonstrate that our ICs resolve previous problems of two-fluid simulations by using variations in particle masses that eliminate （4）表明，通过高阶PT获得的改进与单液体ICS相当，并且（5）证明了Eulerian和Lagrangian模拟之间的出色（即几％的水平），一旦使用高质量的初始条件，就证明了出色的（即几％的水平），这是相当的。伴侣论文介绍了潜在的扰动理论的严格发展。所有介绍的算法均在我们公开可用的Monofonic Music-2软件包中实现。
We present a novel approach to generate higher-order initial conditions (ICs) for cosmological simulations that take into account the distinct evolution of baryons and dark matter. We focus on the numerical implementation and the validation of its performance, based on both collisionless N-body simulations and full hydrodynamic Eulerian and Lagrangian simulations. We improve in various ways over previous approaches that were limited to first-order Lagrangian perturbation theory (LPT). Specifically, we (1) generalize nth-order LPT to multi-fluid systems, allowing 2LPT or 3LPT ICs for two-fluid simulations, (2) employ a novel propagator perturbation theory to set up ICs for Eulerian codes that are fully consistent with 1LPT or 2LPT, (3) demonstrate that our ICs resolve previous problems of two-fluid simulations by using variations in particle masses that eliminate spurious deviations from expected perturbative results, (4) show that the improvements achieved by going to higher-order PT are comparable to those seen for single-fluid ICs, and (5) demonstrate the excellent (i.e., few per cent level) agreement between Eulerian and Lagrangian simulations, once high-quality initial conditions are used. The rigorous development of the underlying perturbation theory is presented in a companion paper. All presented algorithms are implemented in the Monofonic Music-2 package that we make publicly available.
