Probing Modified Gravity Theories with ISW and CMB Lensing
Probing Modified Gravity Theories with ISW and CMB Lensing
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DOI：
10.1093/mnras/stu916
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发表时间：
2014-03
影响因子：
4.8
通讯作者：
D. Munshi;Bin Hu;A. Renzi;A. Heavens;P. Coles
中科院分区：
文献类型：
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作者：
D. Munshi;Bin Hu;A. Renzi;A. Heavens;P. Coles
最近在温度图的双谱中发现了积分Sach s-Wolfe效应（ISW）和宇宙微波背景辐射（CMB）透镜效应的互相关的印记。在本文中，我们使用优化的偏态谱以及与闵可夫斯基泛函（MF）相关的偏态谱来测试使用此信号来检测引力理论偏离广义相对论（GR）的可能性。我们发现，尽管这两种统计量都可以对修正重力施加约束，但优化的斜谱对表示当前时期标量子的康普顿波长的参数B 0特别敏感，并且这两种统计量都可以用来对任何偏离GR的情况施加严格的约束，或者精确地指出数据中的任何系统学。我们研究了三种改进的引力理论，即：后参数化弗里德曼（PPF）形式主义;胡-萨维奇（HS）模型;和Bertschinger-Zukin（BZ）形式主义。对类似于欧空局普朗克使命的实验装置进行似然分析，我们发现，假设GR是正确的模型，我们期望来自前两个偏斜光谱S（0）l和S（1）l的约束是相同的：在95%置信水平（CL）下B 0 < 0.45，在BZ模型中在99%CL下B 0 < 0.67。第三个偏斜谱没有给出任何有意义的约束。MF的性能可以通过使用维纳型滤波来改善，但是我们发现最佳偏斜谱更强大，在95%CL处给出B 0 < 0.071，在99%CL处给出B 0 < 0.15，这与从MF导出的约束相比是六倍的改进，并且基本上与使用全双谱可以实现的相同。
The imprint of the cross-correlation of the Integrated Sach s-Wolfe effect (ISW) and lensing of the cosmic microwave background (CMB) radiation has recently been detected in the bispectrum of temperature maps. In this paper, we use the optimised skew-spectrum as well as skew-spectra associated with Minkowski Functionals (MFs) to test the possibility of using this signal to detect deviations in the theory of gravity away from General Relativity (GR). We fi nd that the although both statistics can put constraints on modified gravity, the optimised skew- spectra are especially sensitive to the parameter B0 that denotes the the Compton wavelengthof the scalaron at the present epoch, and both can be used to put stringent constraints on any departure from GR, or pinpoint any systematics in the data. We investigate three modified gravity theories, namely: the Post-Parametrised Friedmanian (PPF) formalism; the Hu-Sawicki (HS) model; and the Bertschinger-Zukin (BZ) formalism. Employing a likelihood analysis for an experimental setup similar to ESA’s Planck mission, we find that, assuming GR to be the correct model, we expect the constraints from the first two skew-spectra, S (0) l andS (1) l , to be the same: B0 < 0.45 at 95% confidence level (CL), and B0 < 0.67 at 99% CL in the BZ model. The third skew-spectrum does not give any meaningful constraint. The performance of MFs can be improved by using Wiener-type filtering, but we fi nd that the optimal skew-spectrum is much more powerful, giving B0 < 0.071 at 95% CL and B0 < 0.15 at 99% CL, which is a factor of six improvement compared to constraints derived from MF, and essentially identical to what can be achieved using the full bispectrum.