在具有两个各向异性宇宙学模型的五年WMAP数据中CMB局部极值统计量的频率论比较
Frequentist comparison of CMB local extrema statistics in the five-year WMAP data with two anisotropic cosmological models
摘要：
我们提出了两个模型的局部极值研究，引入一个首选的方向观察到的宇宙微波背景（CMB）温度场。特别是，我们做了一个频率论比较的一点和两点的统计偶极子调制和ACW模型的数据从五年威尔金森微波各向异性探测器（WMAP）。这种分析的动机是以前发现的异常WMAP数据，特别是在半球分区分析时的温度各向异性的统计性质的差异。一点统计的分析表明，以前确定的半球方差的困难，显然可以克服由偶极调制场，但新的不一致出现，如果被认为是统计的平均值和L-依赖。局部极值的两点关联函数、温度对乘积和点-点空间对计数表明，这种调制的影响是在比偶极子或四极子波长更小的尺度上使温度场过度“不对称”，这是观测数据所不赞成的，然而，ACW模式预测的结果与标准各向同性假设是一致的。两点分析证实，这种类型的违反各向同性的温度极值统计的影响是相对较弱的。从这项工作中，我们的结论是，需要一个模型与更多的空间结构比偶极调制或旋转不变性破坏模型，以充分解释所观察到的大规模异常的WMAP数据。
英文摘要：
We present local extrema studies of two models that introduce a preferred direction into the observed cosmic microwave background (CMB) temperature field. In particular, we make a frequentist comparison of the one- and two-point statistics for the dipole modulation and ACW models with data from the five-year Wilkinson Microwave Anisotropy Probe (WMAP). This analysis is motivated by previously revealed anomalies in the WMAP data, and particularly the difference in the statistical nature of the temperature anisotropies when analysed in hemispherical partitions. The analysis of the one-point statistics indicates that the previously determined hemispherical variance difficulties can be apparently overcome by a dipole modulation field, but new inconsistencies arise if the mean and the l-dependence of the statistics are considered. The two-point correlation functions of the local extrema, the temperature pair product and the point-point spatial pair-count, demonstrate that the impact of such a modulation is to over-`asymmetrise' the temperature field on smaller scales than the wave-length of the dipole or quadrupole, and this is disfavored by the observed data.The results from the ACW model predictions, however, are consistent with the standard isotropic hypothesis. The two-point analysis confirms that the impact of this type of violation of isotropy on the temperature extrema statistics is relatively weak. From this work, we conclude that a model with more spatial structure than the dipole modulated or rotational-invariance breaking models are required to fully explain the observed large-scale anomalies in the WMAP data.
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。
