CFHTLenS: a Gaussian likelihood is a sufficient approximation for a cosmological analysis of third-order cosmic shear statistics
CFHTLenS: a Gaussian likelihood is a sufficient approximation for a cosmological analysis of third-order cosmic shear statistics
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CFHTLenS：高斯似然对于三阶宇宙剪切统计的宇宙学分析来说是足够的近似
DOI：
10.1093/mnras/stv339
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发表时间：
2015
影响因子：
4.8
通讯作者：
van Waerbeke
中科院分区：
文献类型：
--
作者：
Semboloni;van Waerbeke
利用物质双谱研究了加拿大-法国-夏威夷望远镜透镜巡天（CFHTLenS）中三重源之间的剪切信号的相关性，以探测宇宙学参数。与以前的研究相比，我们采用了一个非高斯模型的数据可能性，这是支持我们的模拟调查。我们发现，对于最先进的调查，类似于CFHTLenS，高斯似然分析是一个合理的近似，尽管参数约束的小差异已经可见。对于未来的调查，我们预计高斯模型将变得不准确。我们的算法，一个精致的非高斯分析和数据压缩，然后是非常有用的，特别是因为它不是更详细，如果模拟数据可用。在盲分析中将该算法应用于单独剪切的三阶关联，我们发现与标准宇宙学模型很好地吻合：对于平坦的Λ冷暗物质宇宙学，h = 0.7 ± 0.04（68%可信区间）。然而，我们的模型仅提供了中等程度的拟合，如χ2/dof = 2.9所示，包括预测信号幅度的20% rms不确定性。该模型不能解释信号下降的规模约15弧分，这可能是由系统性。目前还不清楚这种差异是否可以完全解释的残余点扩散函数系统，我们发现证据至少在几个弧分的尺度。因此，我们需要更好地理解宇宙剪切的高阶关联及其系统学，以便有信心地将它们作为宇宙学探针。
We study the correlations of the shear signal between triplets of sources in the Canada–France–Hawaii Telescope Lensing Survey (CFHTLenS) to probe cosmological parameters via the matter bispectrum. In contrast to previous studies, we adopt a non-Gaussian model of the data likelihood which is supported by our simulations of the survey. We find that for state-of-the-art surveys, similar to CFHTLenS, a Gaussian likelihood analysis is a reasonable approximation, albeit small differences in the parameter constraints are already visible. For future surveys we expect that a Gaussian model becomes inaccurate. Our algorithm for a refined non-Gaussian analysis and data compression is then of great utility especially because it is not much more elaborate if simulated data are available. Applying this algorithm to the third-order correlations of shear alone in a blind analysis, we find a good agreement with the standard cosmological model:for a flat Λ cold dark matter cosmology withh= 0.7 ± 0.04 (68 per cent credible interval). Nevertheless our models provide only moderately good fits as indicated by χ2/dof = 2.9, including a 20 per cent rms uncertainty in the predicted signal amplitude. The models cannot explain a signal drop on scales around 15 arcmin, which may be caused by systematics. It is unclear whether the discrepancy can be fully explained by residual point spread function systematics of which we find evidence at least on scales of a few arcmin. Therefore we need a better understanding of higher order correlations of cosmic shear and their systematics to confidently apply them as cosmological probes.
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设计弱透镜调查：广义本征模分析
DOI：
--
发表时间：
2005
期刊：
影响因子：
--
作者：
M. Kilbinger;Dipak Munshi Universitaet Bonn;I. Cambridge;Cavendish Lab. Cambridge
通讯作者：
Cavendish Lab. Cambridge
影响因子：
6.5
作者：
P. Schneider;T. Eifler;E. K. A. F. Astronomie;U. Bonn;Center for Cosmology;Particle Physics;O. University;C. I. O. Technology.;D. Astronomy
通讯作者：
P. Schneider;T. Eifler;E. K. A. F. Astronomie;U. Bonn;Center for Cosmology;Particle Physics;O. University;C. I. O. Technology.;D. Astronomy
相关函数概率分布的拟高斯近似
影响因子：
6.5
作者：
Wilking;Schneider
通讯作者：
Schneider
影响因子：
6.5
作者：
Hartlap, J.;Simon, P.;Schneider, P.
通讯作者：
Schneider, P.
影响因子：
4.8
作者：
M. Kilbinger;L. Fu;C. Heymans;F. Simpson;J. Benjamin;T. Erben;J. Harnois-Déraps;H. Hoekstra
通讯作者：
M. Kilbinger;L. Fu;C. Heymans;F. Simpson;J. Benjamin;T. Erben;J. Harnois-Déraps;H. Hoekstra