Sufficiency of a Gaussian power spectrum likelihood for accurate cosmology from upcoming weak lensing surveys
Sufficiency of a Gaussian power spectrum likelihood for accurate cosmology from upcoming weak lensing surveys
复制标题
从即将到来的弱透镜巡天中获得准确宇宙学的高斯功率谱可能性的充分性
DOI：
10.1093/mnras/stab522
复制
发表时间：
2021
影响因子：
4.8
通讯作者：
Upham R
中科院分区：
文献类型：
--
作者：
Upham R
我们调查是否高斯似然是足够的，以获得准确的参数约束aeuclid-like相结合的层析功率谱分析弱透镜，星系聚类，和它们的互相关。测试其性能对Wishart分布，这是高斯场的假设下的确切的可能性，在整个天空中，我们发现高斯似然返回准确的参数约束。这种准确性对似然分析中所做的选择是鲁棒的，包括基准宇宙学的选择、所包括的尺度范围和随机噪声水平。我们将我们的结果扩展到切割天空的联合切割天空的可能性在其边缘分布和依赖结构的额外的非高斯性评估。我们发现，切割天空的可能性是更多的非高斯比全天空的可能性，但在一个水平不足以引入显着的不准确性到使用高斯的可能性获得的参数约束。我们的结果不应该受到高斯场假设的影响，因为这种近似只在小尺度上变得不准确，这反过来又对应于任何非高斯似然性变得可以忽略不计的极限。然而，我们比较N体弱透镜模拟，并没有发现显着的额外的非高斯的可能性的证据。我们的研究结果表明，高斯似然将是足够的强大的参数约束与功率谱从第四阶段弱透镜调查。
We investigate whether a Gaussian likelihood is sufficient to obtain accurate parameter constraints from aEuclid-like combined tomographic power spectrum analysis of weak lensing, galaxy clustering, and their cross-correlation. Testing its performance on the full sky against the Wishart distribution, which is the exact likelihood under the assumption of Gaussian fields, we find that the Gaussian likelihood returns accurate parameter constraints. This accuracy is robust to the choices made in the likelihood analysis, including the choice of fiducial cosmology, the range of scales included, and the random noise level. We extend our results to the cut sky by evaluating the additional non-Gaussianity of the joint cut-sky likelihood in both its marginal distributions and dependence structure. We find that the cut-sky likelihood is more non-Gaussian than the full-sky likelihood, but at a level insufficient to introduce significant inaccuracy into parameter constraints obtained using the Gaussian likelihood. Our results should not be affected by the assumption of Gaussian fields, as this approximation only becomes inaccurate on small scales, which in turn corresponds to the limit in which any non-Gaussianity of the likelihood becomes negligible. We nevertheless compare against N-body weak lensing simulations and find no evidence of significant additional non-Gaussianity in the likelihood. Our results indicate that a Gaussian likelihood will be sufficient for robust parameter constraints with power spectra from stage IV weak lensing surveys.
登录
查看更多内容
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：
8.6
作者：
Masanori Sato;K. Ichiki;T. Takeuchi
通讯作者：
Masanori Sato;K. Ichiki;T. Takeuchi
非高斯似然的快速、始终正定且可归一化的近似
DOI：
--
发表时间：
2015
期刊：
影响因子：
--
作者：
E. Sellentin
通讯作者：
E. Sellentin
影响因子：
4.8
作者：
Clerkin, L.;Kirk, D.;Walker, A. R.
通讯作者：
Walker, A. R.
来自相关高斯宇宙学场的伪 Cℓ 估计的精确联合似然
影响因子：
4.8
作者：
R. E. Upham;L. Whittaker;Michael L. Brown
通讯作者：
Michael L. Brown