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Testing the Gaussianity of the COBE-DMR data with spherical wavelets

R. B. Barreiro·M. P. Hobson·A. N. Lasenby·A. J. Banday·K. M. Gorski·G. Hinshaw
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Abstract

We investigate the Gaussianity of the 4-year COBE-DMR data (in HEALPix pixelisation) using an analysis based on spherical Haar wavelets. We use all the pixels lying outside the Galactic cut and compute the skewness, kurtosis and scale-scale correlation spectra for the wavelet coefficients at each scale. We also take into account the sensitivity of the method to the orientation of the input signal. We find a detection of non-Gaussianity at $> 99$ per cent level in just one of our statistics. Taking into account the total number of statistics computed, we estimate that the probability of obtaining such a detection by chance for an underlying Gaussian field is 0.69. Therefore, we conclude that the spherical wavelet technique shows no strong evidence of non-Gaussianity in the COBE-DMR data.

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R. B. Barreiro, M. P. Hobson, A. N. Lasenby, A. J. Banday, K. M. Gorski, G. Hinshaw. 2000-04-14. Testing the Gaussianity of the COBE-DMR data with spherical wavelets. https://doi.org/10.1046/j.1365-8711.2000.03772.x

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