发表机构
The Institute of Mathematical Sciences; Homi Bhabha National Institute; Korea Astronomy and Space Science Institute; INAF/OAS Bologna, Osservatorio di Astrofisica e Scienza dello Spazio, Area della ricerca CNR-INAF; Department of Physics and Astronomy, Sejong University; University of Science and Technology（马哈拉施特拉数学科学研究所; 霍米·巴巴国家研究所; 韩国天体与空间科学研究院; 意大利国家天体物理研究所/博洛尼亚天文台与空间科学观测站，CNR-INAF研究区; 世宗大学物理与天文学系; 科学技术大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用协方差加权改进Richardson-Lucy反卷积算法，从CMB透镜测量中重建物质功率谱，发现非线性演化解释增强，且保留BAO信息。
AI 中文摘要
物质功率谱是宇宙大尺度物质分布的主要统计描述量之一，为宇宙结构形成提供了强有力的探针。对宇宙微波背景（CMB）透镜效应的测量提供了跨越广泛红移范围的物质分布综合视图，使得重建潜在的物质功率谱成为可能。在本工作中，我们使用协方差加权的改进Richardson-Lucy（MRL）反卷积算法，从Planck PR4、ACT DR6和SPT-3G的基线联合CMB透镜测量中重建了参考线性物质功率谱$P_\text{lin}(k,0)$。重建的谱在大尺度上与基准线性预测一致，而在$k \trsim 0.1\rm{Mpc}^{-1}$处表现出系统性增强，此时非线性引力演化变得重要。为了研究这一行为，我们引入了一个尺度相关的修正因子$A(k)$，定义为$P(k)=A(k)P_{\rm nl}(k)$，其中$P_{\rm nl}(k)$是从2LPT模拟获得的基准非线性物质功率谱。重建的修正因子在重建范围内与1在$2\sigma$置信度内保持一致，表明观测到的增强可被标准非线性物质功率谱演化很好地解释。此外，重建结果在$k\sim(0.04-0.06)\rm{Mpc}^{-1}$的BAO特征附近与基准BAO模板一致，表明一些BAO尺度信息在透镜投影中得以保留。
英文摘要
The matter power spectrum is one of the primary statistical descriptors of the large-scale distribution of matter in the Universe and provides a powerful probe of cosmic structure formation. Measurements of cosmic microwave background (CMB) lensing offer an integrated view of the matter distribution over a wide range of redshifts, enabling the reconstruction of the underlying matter power spectrum. In this work, we reconstruct the reference linear matter power spectrum $ P_\text{lin}(k,0)$ from the baseline joint CMB lensing measurements of Planck PR4, ACT DR6, and SPT-3G using a covariance-weighted modified Richardson-Lucy(MRL) deconvolution algorithm. The reconstructed spectrum is found to be consistent with the fiducial linear prediction on large scales, while exhibiting a systematic enhancement for $k \gtrsim 0.1\,{\rm Mpc}^{-1}$, where nonlinear gravitational evolution becomes important. To investigate this behavior, we introduce a scale-dependent correction factor, $A(k)$, defined through $P(k)=A(k)\,P_{\rm nl}(k),$ where $P_{\rm nl}(k)$ is the fiducial nonlinear matter power spectrum obtained from 2LPT simulations. The reconstructed correction factor remains consistent with unity within $2σ$ confidence over the reconstructed range, indicating that the observed enhancement is well explained by the standard nonlinear evolution of the matter power spectrum. In addition, the reconstruction shows agreement with the fiducial BAO template around the BAO feature at $k\sim(0.04-0.06)\ {\rm Mpc}^{-1}$, indicating that some BAO-scale information survives the lensing projection.
Commentsv1: 18 pages and 5 figures
