论文标题

用多尺度镜头PDF增强宇宙剪切

Enhancing cosmic shear with the multi-scale lensing PDF

论文作者

Giblin, Benjamin, Cai, Yan-Chuan, Harnois-Déraps, Joachim

论文摘要

我们通过用对$ W $ CDM COSMIC镜头剪切模拟的模拟器对该统计量进行建模,从而量化了“镜头PDF”的宇宙学约束能力 - 弱透镜收敛图的单点概率密度。 After validating our methods on Gaussian and lognormal fields, we show that `multi-scale' PDFs - measured from maps with multiple levels of smoothing - offer considerable gains over two-point statistics, owing to their ability to extract non-Gaussian information: for a mock Stage-III survey, lensing PDFs yield 33\% tighter constraints on the clustering parameter $ s_8 =σ_8\ sqrt {ω_ {\ rm m} /0.3} $比两点剪切相关函数。对于阶段IV调查,我们在$ s_8 $上获得了$> $ 90 \%的限制,但也可以在州参数的哈勃和暗能量方程式上获得。有趣的是,我们仅在我们的III阶段设置中将这两个探针组合在一起时会发现改进。在阶段IV方案中,镜头PDF包含来自标准两点统计的所有信息等。这表明,尽管这两个探针目前是互补的,但即将进行的调查的较低噪声水平将释放PDF的约束功率。

We quantify the cosmological constraining power of the `lensing PDF' - the one-point probability density of weak lensing convergence maps - by modelling this statistic numerically with an emulator trained on $w$CDM cosmic shear simulations. After validating our methods on Gaussian and lognormal fields, we show that `multi-scale' PDFs - measured from maps with multiple levels of smoothing - offer considerable gains over two-point statistics, owing to their ability to extract non-Gaussian information: for a mock Stage-III survey, lensing PDFs yield 33\% tighter constraints on the clustering parameter $S_8=σ_8\sqrt{Ω_{\rm m}/0.3}$ than the two-point shear correlation functions. For Stage-IV surveys, we achieve $>$90\% tighter constraints on $S_8$, but also on the Hubble and dark energy equation of state parameters. Interestingly, we find improvements when combining these two probes only in our Stage-III setup; in the Stage-IV scenario the lensing PDFs contain all information from the standard two-point statistics and more. This suggests that while these two probes are currently complementary, the lower noise levels of upcoming surveys will unleash the constraining power of the PDF.

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