快速射电暴色散量的单圈功率谱
The One-Loop Power Spectrum of Fast Radio Burst Dispersion Measures
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中文总结 AI 辅助
该研究构建自由电子自功率谱与电子-星系交叉功率谱的单圈EFT描述，结合FLAMINGO模拟验证模型，确立自由电子为抗反馈的近无偏物质示踪物，为FRB相关宇宙学研究提供理论基础。
中文摘要 AI 辅助
快速射电暴（FRB）的色散量追踪自由电子柱密度，很快将成为探测低红移重子的独特探针。这类测量可直接约束宇宙学，自由电子作为大尺度结构的新示踪物，还能探测星系的重子反馈，这是LSST和Euclid等弱引力透镜巡天的主要系统误差源。我们使用有效场论（EFT）和流体动力学模拟为这两个科学场景做准备。我们构建了自由电子自功率谱$P_{ee}$和电子-星系交叉功率谱$P_{eg}$的单圈EFT描述，将FRB色散聚类置于与光谱星系分析相同的理论基础上，并量化了该建模适用的FRB密度。我们还研究了适合交叉关联的星系样本，发现当前光谱星表提供了合适的红移范围和足够的密度。我们针对FLAMINGO模拟验证了该模型，在$z=0.2$和0.5处对类DESI样本的$P_{ee}$、$P_{eg}$和$P_{gg}$进行联合拟合。该模型在$k\backsim0.2h{\rm Mpc}^{-1}$范围内描述了所有三个功率谱，电子线性偏置$b_{e,1}\backsim0.92$，高阶偏置与零一致，且所有参数在不同反馈变体中稳定。结合近乎完美的电子-物质关联$r_{em}\backsim1$，这确立了自由电子是几乎无偏、抗反馈的物质示踪物，支持基于FRB的反馈约束的关键假设。这些特性使电子聚类成为混合有效场论（HEFT）的理想应用，HEFT将使建模范围再扩展2-3倍。低红移电子谱在下一代巡天最初几年的线性区域之外将成为信号主导；本研究开发的模型在这些时间尺度上是必要的。
英文摘要
Fast radio burst (FRB) dispersion measures trace free electron column densities and will soon offer a unique probe of low-$z$ baryons. Such measurements can constrain cosmology directly, with the free electrons serving as a new tracer of large-scale structure, and probe the baryonic feedback of galaxies, a leading systematic for weak lensing surveys such as LSST and Euclid. We prepare for both science cases using effective field theory (EFT) and hydrodynamical simulations. We construct the one-loop EFT description of the free-electron auto-spectrum $P_{ee}$ and electron-galaxy cross-spectrum $P_{eg}$, placing FRB dispersion clustering on the same theoretical footing as spectroscopic galaxy analyses, and quantify the FRB densities at which this modeling is useful. We also investigate suitable galaxy samples for cross-correlations, finding that current spectroscopic catalogs provide appropriate redshift range and sufficient density. We validate the model against the FLAMINGO simulations, jointly fitting $P_{ee}$, $P_{eg}$, and $P_{gg}$ for DESI-like samples at $z=0.2$ and 0.5. The model describes all three spectra to $k\sim0.2\,h\,{\rm Mpc}^{-1}$, with an electron linear bias $b_{e,1}\simeq0.92$, higher-order biases consistent with zero, and all parameters stable across feedback variants. Together with the near-perfect electron-matter correlation $r_{em}\simeq1$, this establishes free electrons as nearly unbiased, feedback-robust tracers of matter, supporting a key assumption of FRB-based feedback constraints. These properties make electron clustering an ideal application for Hybrid Effective Field Theory (HEFT), which would extend the modeling reach by a further factor of 2--3. The low-$z$ electron spectrum becomes signal-dominated beyond the linear regime within the first few years of next-generation surveys; the models developed here will be necessary on these timescales.
