The imprint of f(R) gravity on weak gravitational lensing - II. Information content in cosmic shear statistics
The imprint of f(R) gravity on weak gravitational lensing - II. Information content in cosmic shear statistics
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DOI：
10.1093/mnras/stw3254
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发表时间：
2016-10
影响因子：
4.8
通讯作者：
M. Shirasaki;T. Nishimichi;Baojiu Li;Y. Higuchi
中科院分区：
文献类型：
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作者：
M. Shirasaki;T. Nishimichi;Baojiu Li;Y. Higuchi
我们调查的信息内容的各种宇宙剪切统计引力理论。针对Hu-Sawicki型f（R）模型，我们进行了一组光线跟踪模拟，并测量了收敛双谱、峰数和Minkowski泛函。我们首先证明，虽然收敛功率谱确实对额外标量自由度的当前值敏感，|fR0|在此基础上，密度振幅参数σ_8和物质密度参数Ω_m_0的变化在很大程度上补偿了这一变化。从1000个透镜模拟获得准确的协方差矩阵，然后我们检查三个额外的统计量的约束能力。我们发现，这些探针确实有助于打破参数简并，这不能单独从功率谱解决。我们表明，特别是峰值计数和闵可夫斯基泛函有可能严格（边缘）检测与参数的修改重力签名|fR0|小到10−5（10−6），如果我们能够在未来的1500 deg 2天空覆盖范围的调查中在小（101 arcmin）尺度上适当地对它们进行建模。我们还表明，信号电平是类似的额外的三个统计量，它们都提供了补充信息的功率谱。这些发现表明，在标准功率谱分析之外结合多个探测器来检测广义相对论可能的修改的重要性。
We investigate the information content of various cosmic shear statistics on the theory of gravity. Focusing on the Hu–Sawicki-type f(R) model, we perform a set of ray-tracing simulations and measure the convergence bispectrum, peak counts and Minkowski functionals. We first show that while the convergence power spectrum does have sensitivity to the current value of extra scalar degree of freedom |fR0|, it is largely compensated by a change in the present density amplitude parameter σ8 and the matter density parameter Ωm0. With accurate covariance matrices obtained from 1000 lensing simulations, we then examine the constraining power of the three additional statistics. We find that these probes are indeed helpful to break the parameter degeneracy, which cannot be resolved from the power spectrum alone. We show that especially the peak counts and Minkowski functionals have the potential to rigorously (marginally) detect the signature of modified gravity with the parameter |fR0| as small as 10−5 (10−6) if we can properly model them on small (∼1 arcmin) scale in a future survey with a sky coverage of 1500 deg2. We also show that the signal level is similar among the additional three statistics and all of them provide complementary information to the power spectrum. These findings indicate the importance of combining multiple probes beyond the standard power spectrum analysis to detect possible modifications to general relativity.