Regional anomalies of cosmic microwave background power spectrum

  • Published : 2018.05.08

Abstract

We analyze the Planck 2015 cosmic microwave background temperature fluctuation data to find any anomaly in the angular power spectra measured for partial regions on the sky. For disks with radius of $20^{\circ}$, $45^{\circ}$ and $90^{\circ}$, which are densely overlapping on the sky, we estimate the power excess and its statistical significance relative to the LambdaCDM expectation for some chosen ranges of angular scales. We also investigate the dipolar asymmetry using the power excess maps obtained for some chosen angular scales, and confirm the previously announced consistent dipole directions. The average dipole amplitude and the inner products of dipoles have been measured from the power excess maps at different angular scales. We conclude that although dipole directions are consistent the measured amplitudes are not statistically significant compared to the LambdaCDM model prediction.

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