红移空间中场级分析的宇宙学信息
Cosmological information from field-level analysis in redshift space
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- Ludwig-Maximilians-Universität（路德维希-马克西米利安大学）
- Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）
- Excellence Cluster ORIGINS（ORIGINS卓越集群）
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中文总结 AI 辅助
本研究利用LEFTfield正向模型，基于DESI LRG类红移空间模拟，量化场级分析相对功率谱和双谱的精度提升，发现其可显著提高原初振幅等参数测量精度，凸显其未来发现潜力。
中文摘要 AI 辅助
基于大尺度结构有效场论的正向模型的星系成团场级分析，能够以最优统计精度提供宇宙学测量，同时对于星系形成相关的理论不确定性具有鲁棒性。然而，在微扰论区域内，场级分析相对于当前由功率谱和双谱组合所设定的最先进水平，其定量增益并不明显，且取决于分析选择、宇宙学模型以及观测到的星系种群。因此，我们量化了场级分析相对于功率谱和双谱在红移空间快照上的精度提升，这些快照与DESI LRG样本高度相似。我们的模拟数据由LEFTfield正向模型生成，该模型也用于后续的场级分析以及功率谱和双谱精度的Fisher预测。我们发现，对于ΛCDM宇宙学，场级分析相对于功率谱和双谱有显著改进；特别是原初涨落振幅的测量精度可提高两倍。对于功率谱形状与结构增长之间具有更灵活依赖关系的扩展宇宙学，场级分析的精度增益更为显著；在原初振幅方面可达三倍，在捕捉偏离ΛCDM的参数方面可达两倍。我们的结果凸显了场级分析在未来发现中的潜力。实现这一潜力需要在观测建模、观测系统效应以及数值推断技术方面进行实质性发展。
英文摘要
The field-level analysis of galaxy clustering with a forward model based on the Effective Field Theory of Large Scale structure provides cosmological measurements at optimal statistical precision which are simultaneously robust with respect to theoretical uncertainties regarding galaxy formation. Yet, the quantitative gains of field-level analysis in the perturbative regime over the current state-of-the-art, set by the combination of power- and bispectrum, are not obvious, and they depend on analysis choices, the cosmological model, and the observed galaxy population. We therefore quantify the precision improvement from field-level analysis over power- and bispectrum from redshift-space snapshots that closely resemble the DESI LRG sample. Our mock data are created with the LEFTfield forward model, which we also use for the subsequent field-level analysis and for a Fisher forecast of the power- and bispectrum precision. We find significant improvements from the field-level analysis over the power- and bispectrum for a $Λ$CDM cosmology; in particular the primordial fluctuation amplitude can be measured twice as precisely. Precision gains at the field-level are even more pronounced for extended cosmologies with a more flexible dependence between power spectrum shape and structure growth; they reach up to a factor of three in the primordial amplitude and a factor of two in parameters that capture deviations from $Λ$CDM. Our results highlight the potential of field-level analysis for future discoveries. Realizing this potential will require substantial developments on the modeling of observations and observational systematics as well as on the numerical inference techniques.
