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arXiv 1011.2640astro-ph.COhep-thphysics.data-an
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宇宙微波背景辐射的能级交叉分析:一种探测宇宙弦的方法

Level Crossing Analysis of Cosmic Microwave Background Radiation: A method for detecting cosmic strings

M. Sadegh Movahed, Shahram Khosravi

摘要:

本文研究了极早期宇宙中作为拓扑缺陷的宇宙弦对宇宙微波背景辐射的影响。我们开发的水平交叉分析的方法在著名的Kaiser-Stebbins现象的背景下,探索宇宙弦的签名。我们用WMAP-7给出的最佳拟合参数模拟了一个高斯映射,然后用非相干的、活跃的涨落来模拟宇宙弦效应。为了研究我们的方法检测宇宙弦的张力,$Gμ$的不同值的能力,一个模拟的纯高斯映射进行了比较,包括宇宙弦。通过能级交叉分析,在没有仪器噪声和分辨率为$R=1'$的模拟图中,可以探测到叠加有$Gμ\gtrsim 4\times 10^{-9}$的宇宙弦。在存在预期的仪器噪声的情况下,下限刚好增加到$Gμ\gtrsim 5.8\times 10^{-9}$。

英文摘要:

In this paper we study the footprint of cosmic string as the topological defects in the very early universe on the cosmic microwave background radiation. We develop the method of level crossing analysis in the context of the well-known Kaiser-Stebbins phenomenon for exploring the signature of cosmic strings. We simulate a Gaussian map by using the best fit parameter given by WMAP-7 and then superimpose cosmic strings effects on it as an incoherent and active fluctuations. In order to investigate the capability of our method to detect the cosmic strings for the various values of tension, $Gμ$, a simulated pure Gaussian map is compared with that of including cosmic strings. Based on the level crossing analysis, the superimposed cosmic string with $Gμ\gtrsim 4\times 10^{-9}$ in the simulated map without instrumental noise and the resolution $R=1'$ could be detected. In the presence of anticipated instrumental noise the lower bound increases just up to $Gμ\gtrsim 5.8\times 10^{-9}$.

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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