Reconstructing the primordial power spectrum—a new algorithm
Reconstructing the primordial power spectrum—a new algorithm
复制标题
重建原始功率谱——一种新算法
DOI：
10.1088/1475-7516/2004/04/002
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发表时间：
2003
影响因子：
6.4
通讯作者：
S. Hannestad
中科院分区：
文献类型：
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作者：
S. Hannestad
本文提出了一种有效的、与模型无关的方法，用于从宇宙微波背景辐射和大尺度结构观测数据中重建原始功率谱。该算法是基于蒙特卡洛原理，因此非常简单，纳入现有的代码，如马尔可夫链蒙特卡洛之一。该算法已被用于目前的宇宙学数据测试的原始功率谱的功能。没有显着的证据的功能被发现，虽然有轻微的偏好，整体弯曲的频谱，以及在非常大的规模的功率下降。我们还测试了模拟高精度CMB数据，计算模型与非尺度不变的原始光谱的算法。该算法有效地提取了潜在的光谱，以及在每种情况下的其他宇宙学参数。最后，我们使用的算法在一个模型中，一个人为的毛刺在CMB频谱已被施加，如在WMAP数据中看到的。在这种情况下，它被发现，虽然基本的宇宙学参数可以被提取，恢复的功率谱可以显示出显着的虚假功能，如弯曲，即使真正的频谱是标度不变的。
We propose an efficient and model independent method for reconstructing the primordial power spectrum from cosmic microwave background (CMB) and large scale structure observations. The algorithm is based on a Monte Carlo principle and therefore very simple to incorporate into existing codes such as the Markov chain Monte Carlo one. The algorithm has been used on present cosmological data to test for features in the primordial power spectrum. No significant evidence for features is found, although there is a slight preference for an overall bending of the spectrum, as well as a decrease in power at very large scales. We have also tested the algorithm on mock high precision CMB data, calculated from models with non-scale-invariant primordial spectra. The algorithm efficiently extracts the underlying spectrum, as well as the other cosmological parameters in each case. Finally we have used the algorithm on a model where an artificial glitch in the CMB spectrum has been imposed, like the ones seen in the WMAP data. In this case it is found that, although the underlying cosmological parameters can be extracted, the recovered power spectrum can show significant spurious features, such as bending, even if the true spectrum is scale invariant.