发表机构
Institute of Space Sciences (ICE, CSIC); Universitat Autònoma de Barcelona (UAB); Institut de Física d’Altes Energies (IFAE); The Barcelona Institute of Science and Technology（空间科学研究所; 巴塞罗那自治大学; 高能物理研究所; 巴塞罗那科学技术研究院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对深度测光样本中放大效应信号被正负响应抵消的问题，提出按响应符号和幅度划分样本的BigMag方法，结合IGGL可达到与传统2x2pt/3x2pt相当的宇宙学约束能力。
AI 中文摘要
星系成团和弱引力透镜是强大的宇宙学探针，传统上通过星系成团和星系-星系透镜在$2\times2$pt分析中结合使用。另一种方法是利用透镜放大效应引起的前景-背景成团互相关，但这类测量的信噪比低于基于剪切的透镜测量。我们表明，对于深度测光样本，具有正和负放大响应的星系之间的抵消会抑制该信号。利用DES第六年测光数据和Balrog合成源注入，我们探索了按放大响应符号和幅度划分的高红移（$z\simeq0.7$-$2.5$）样本。这种划分减少了抵消，并能同时提高信噪比和宇宙学约束能力。我们将前景成团与使用响应选择的背景样本的前景-背景互相关的组合称为BigMag。使用类似DES的模拟数据向量进行的预测表明，对于乐观的样本配置和足够精确的响应校准，BigMag仅利用星系位置即可达到与传统$2\times2$pt相当的约束能力。相同的样本还增强了逆星系-星系透镜（IGGL），这是一种当位置样本位于形状样本之后时由放大效应主导的位置-剪切相关性。将BigMag和IGGL结合进一步自校准放大响应，并产生与传统$3\times2$pt分析相当的边际化$S_8$约束，在本文考虑的更精确校准场景下约束更紧。该框架还为传统$3\times2$pt和几何透镜比率分析提供了近零响应样本。这些结果激励进一步优化和验证星系选择，以实现放大效应作为互补的宇宙学探针。[Abrg.]
英文摘要
Galaxy clustering and weak gravitational lensing are powerful cosmological probes, traditionally combined through galaxy clustering and galaxy-galaxy lensing in a $2\times2$pt analysis. An alternative is the foreground-background clustering cross-correlation induced by lensing magnification, but measurements have achieved lower signal-to-noise than shear-based lensing. We show that, for deep photometric samples, cancellation between galaxies with positive and negative magnification responses can suppress this signal. Using DES Year 6 photometry and Balrog synthetic-source injections, we explore high-redshift ($z\simeq0.7$-$2.5$) samples split by the sign and amplitude of their magnification response. This separation reduces cancellation and can increase both signal-to-noise and cosmological constraining power. We call the combination of foreground clustering and foreground-background cross-correlations with response-selected background samples BigMag. Forecasts with DES-like simulated data vectors show that, for an optimistic sample configuration and sufficiently precise response calibration, BigMag can achieve constraining power comparable to traditional $2\times2$pt using galaxy positions alone. The same samples also enhance inverse galaxy-galaxy lensing (IGGL), a position-shear correlation dominated by magnification when the position sample lies behind the shape sample. Combining BigMag and IGGL further self-calibrates the magnification responses and yields marginalized $S_8$ constraints comparable to traditional $3\times2$pt analyses, and tighter for the more precise calibration scenarios considered here. The framework also enables near-zero-response samples for traditional $3\times2$pt and geometric lensing-ratio analyses. These results motivate further optimization and validation of galaxy selections to realize magnification as a complementary cosmological probe. [Abrg.]
Comments39 pages, 19 figures, 5 tables, 4 appendices
