标题： 使用微扰技术对再电离进行超大规模流体动力学模拟 显示英文标题

标题： Supersizing hydrodynamical simulations of reionization using perturbative techniques

摘要： 我们证明，受有效场理论（EFT）启发的微扰技术可以仅使用基本的线性密度场来“绘制”再电离期间的21厘米信号。 该方法在大尺度上的精度达到O(10%)，因此可以用来扩大或“放大”流体动力学模拟。 特别是，EFT提供了一种在实空间和红移空间中线性密度场与非线性示踪场之间的映射。 我们表明，可以通过THESAN模拟套件从相对较小的模拟体积中可靠地提取这种映射，该模拟套件的共动体积为(95.5 Mpc)^3。 具体来说，我们表明，如果我们在模拟的小约5%的子体积中拟合EFT系数，那么只需线性密度场就可以准确预测模拟其余部分的21厘米信号。 我们表明，我们的技术对不同的暗物质模型和次网格再电离建模差异具有鲁棒性。 显示英文摘要

摘要： We show that perturbative techniques inspired by effective field theory (EFT) can be used to "paint on" the 21~cm field during reionization using only the underlying linear density field. This procedure is accurate to within O(10%) on large scales and thus can be used to enlarge or "supersize" hydrodynamical simulations. In particular, the EFT provides a mapping between the linear density field and a nonlinear tracer field, both in real and redshift space. We show that this mapping can be reliably extracted from relatively small simulation volumes using the THESAN suite of simulations, which have a comoving volume of (95.5 Mpc)^3. Specifically, we show that if we fit the EFT coefficients in a small ~5% sub-volume of the simulation, we can accurately predict the 21cm field in the rest of the simulation given only the linear density field. We show that our technique is robust to different models of dark matter and differences in the sub-grid reionization modeling.