提出快速精确的宇宙物质功率谱公式，支持中微子质量与暗能量演化模型。
syren-new: Precise formulae for the linear and nonlinear matter power spectra with massive neutrinos and dynamical dark energy
- 基于符号回归构建含中微子和动态暗能量的功率谱解析表达式
- 线性与非线性功率谱误差分别仅0.3%和1.3%，匹配高精度模拟结果
- 计算速度比传统数值模拟快十倍以上，适合大规模观测数据处理
当前及未来的大尺度结构巡天旨在约束中微子质量和暗能量状态方程。本文构建了在包含中微子质量和非恒定暗能量状态方程的扩展ΛCDM模型下，线性和非线性物质功率谱的精确且可解释的符号近似公式，扩展了syren-halofit框架，命名为syren-new（SYmbolic-Regression-ENhanced power spectrum emulator with NEutrinos and W₀-wₐ）。同时获得这些模型下推导参数σ₈的简化表达式。线性功率谱逼近CLASS模拟，非线性部分匹配EuclidEmulator2结果。与现有模拟器和N体模拟对比显示，σ₈、线性和非线性功率谱的均方根误差分别为0.1%、0.3%和1.3%，覆盖广泛参数空间、红移和波数范围。验证表明，模拟器误差远小于未来如LSST巡天的观测误差和其他建模不确定性。所提公式精度与现有数值模拟器相当，但在CPU和GPU上至少快一个数量级。代码已公开。
原文摘要 · Abstract (English)
Current and future large scale structure surveys aim to constrain the neutrino mass and the equation of state of dark energy. We aim to construct accurate and interpretable symbolic approximations to the linear and nonlinear matter power spectra as a function of cosmological parameters in extended $Λ$CDM models which contain massive neutrinos and non-constant equations of state for dark energy. This constitutes an extension of the syren-halofit emulators to incorporate these two effects, which we call syren-new (SYmbolic-Regression-ENhanced power spectrum emulator with NEutrinos and $W_0-w_a$). We also obtain a simple approximation to the derived parameter $σ_8$ as a function of the cosmological parameters for these models. Our results for the linear power spectrum are designed to emulate CLASS, whereas for the nonlinear case we aim to match the results of EuclidEmulator2. We compare our results to existing emulators and $N$-body simulations. Our analytic emulators for $σ_8$, the linear and nonlinear power spectra achieve root mean squared errors of 0.1%, 0.3% and 1.3%, respectively, across a wide range of cosmological parameters, redshifts and wavenumbers. We verify that emulator-related discrepancies are subdominant compared to observational errors and other modelling uncertainties when computing shear power spectra for LSST-like surveys. Our expressions have similar accuracy to existing (numerical) emulators, but are at least an order of magnitude faster, both on a CPU and GPU. Our work greatly improves the accuracy, speed and range of applicability of current symbolic approximations to the linear and nonlinear matter power spectra. We provide publicly available code for all symbolic approximations found.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品；中文卡片由大模型生成，请以原文为准。