指導教授:闕志鴻臺灣大學:天文物理研究所黃聖凱Kai, Shen-ShenShen-ShenKai2014-11-252018-06-282014-11-252018-06-282014http://ntur.lib.ntu.edu.tw//handle/246246/261073宇宙微波背景輻射的極化可被分解為E type 與B type 兩個部分。當 觀測的天區很小時(小於十度),我們可以用卡氏座標來分析資料並且 忽略資料背景的曲率。但如果我們想要分析來自更大天區的資料那麼 資料的背景曲率便不可忽略。我們使用球極平面投影的座標來達成此 目的。球極平面投影座標是一個對稱且正交的座標系統,並且在小天 區時逼近卡氏座標,因此我們能產生較準確的E 和B 模來分析背景天 區較大的資料。The CMB polarization can be decomposed into E and B components. Usually when the portion of the sky is small enough(less than 10 degrees), we can analyze the field in Cartesian coordinates by taking the small-scale approximation and neglect the curvature effect. But if we want to analyze the field in a larger portion of the sky we must take the curvature into account. To include the curvature we introduce the stereographic coordinates for the sphere. It is an orthogonal symmetric coordinate that reduces to Cartesian coordinates in the small-sky limit. Hence we can generate more precise basis E and B modes and analyze the field in larger sky.口試委員會審定書iii 誌謝v 摘要vii Abstract ix 1 Introduction 1 2 Preliminaries 3 2.1 Observational parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Stereographic coordinate . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Separation Method 9 3.1 The construction of the filter . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2 The recovered polarization . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.3 The decomposition method for the orthogonal basis . . . . . . . . . . . . 11 4 Results and Discussion 15 4.1 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 5 Future Prospect 23 6 Conclusion 27 xi A Appendix 29 A.1 Formulas in the stereographic plane . . . . . . . . . . . . . . . . . . . . 29 A.2 Formulas for generating cmb data . . . . . . . . . . . . . . . . . . . . . 31 Bibliography 336655260 bytesapplication/pdf論文公開時間:2014/08/25論文使用權限:同意有償授權(權利金給回饋學校)微波背景分割球極平面座標下微波背景輻射E/B 分割之分析Analysis of E/B Decomposition in Stereographic Coordinatesthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/261073/1/ntu-103-R00244007-1.pdf