Isotropy of the early universe from CMB anisotropies

被引:48
作者
Donoghue, EP [1 ]
Donoghue, JF
机构
[1] Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA
[2] Univ Notre Dame, Notre Dame, IN 46556 USA
来源
PHYSICAL REVIEW D | 2005年 / 71卷 / 04期
关键词
D O I
10.1103/PhysRevD.71.043002
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The acoustic peak in the cosmic microwave background power spectrum is sensitive to causal processes and cosmological parameters in the early universe up to the time of last scattering. We provide limits on correlated spatial variations of the peak height and peak position and interpret these as constraints on the spatial variation of the cosmological parameters (baryon density, cold dark matter density, and cosmological constant as well as the amplitude and tilt of the original fluctuations). We utilize recent work of Hansen, Banday, and Gorski who have studied the spatial isotropy of the power spectrum as measured by WMAP by performing the power spectrum analysis on smaller patches of the sky. We find that there is no statistically significant correlated asymmetry of the peak. Hansen, Banday, and Gorski have also provided preliminary indications of a preferred direction in the lower angular momentum range (lsimilar to2-40) and we show how possible explanations of this asymmetry are severely constrained by the data on the acoustic peak. Finally we show a possible non-Gaussian feature in the data, associated with a difference in the northern and southern galactic hemispheres.
引用
收藏
页码:043002 / 1
页数:6
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