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arXiv 1303.6550astro-ph.CO
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宇宙微波背景极化弱透镜效应的高精度模拟

High precision simulations of weak lensing effect on Cosmic Microwave Background polarization

Giulio Fabbian, Radek Stompor

摘要:

我们研究的准确性,鲁棒性和自一致性的像素域模拟的引力透镜的影响,由于宇宙的大尺度结构的原始CMB各向异性。特别是,我们调查的结果精度对这些技术的一些关键参数的依赖,并提出了一个半分析框架,以确定其值,所以所需的精度是先验保证和数值工作量同时优化。我们的重点是B模式信号,但我们也讨论其他CMB观测,如总强度,T和E模式偏振,强调所有这些情况下的差异和相似之处。我们的半解析的考虑得到了广泛的数值结果的支持。这些都是使用一个代码,昵称为lenS 2 HAT-透镜使用可缩放的球面谐波变换(S2 HAT)-我们已经在这项工作的过程中开发。该代码实现了Lewis(2005)的像素域方法的一个版本,并允许以非常高的分辨率和数据量执行模拟,这要归功于S2 HAT库提供的高效并行化-一个用于计算球谐变换的并行库。该代码是公开的。

英文摘要:

We study accuracy, robustness and self-consistency of pixel-domain simulations of the gravitational lensing effect on the primordial CMB anisotropies due to the large-scale structure of the Universe. In particular, we investigate dependence of the results precision on some crucial parameters of such techniques and propose a semi-analytic framework to determine their values so the required precision is a priori assured and the numerical workload simultaneously optimized. Our focus is on the B-mode signal but we discuss also other CMB observables, such as total intensity, T, and E-mode polarization, emphasizing differences and similarities between all these cases. Our semi-analytic considerations are backed up by extensive numerical results. Those are obtained using a code, nicknamed lenS2HAT -- for Lensing using Scalable Spherical Harmonic Transforms (S2HAT) -- which we have developed in the course of this work. The code implements a version of the pixel-domain approach of Lewis (2005) and permits performing the simulations at very high resolutions and data volumes, thanks to its efficient parallelization provided by the S2HAT library -- a parallel library for a calculation of the spherical harmonic transforms. The code is made publicly available.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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