AAS 197, January 2001
Session 72. Cosmology from z=1100 to 1
Display, Wednesday, January 10, 2001, 9:30am-7:00pm, Exhibit Hall

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[72.02] Statistical Power, the Bispectrum and the Search for Non-Gaussianity in the CMB Anisotropy

N. Phillips (RITSS/GSFC/NASA), A. Kogut (GSFC/NASA)

We use simulated maps of the cosmic microwave background anisotropy to quantify the ability of different statistical tests to discriminate between Gaussian and non-Gaussian models. Despite the central limit theorem on large angular scales, both the genus and extrema correlation are able to discriminate between Gaussian models and a semi-analytic texture model selected as a physically motivated non-Gaussian model. When run on the COBE 4-year CMB maps, both tests prefer the Gaussian model. Although the bispectrum has comparable statistical power when computed on the full sky, once a Galactic cut is imposed on the data the bispectrum loses the ability to discriminate between models. Off-diagonal elements of the bispectrum are comparable to the diagonal elements for the non-Gaussian texture model and must be included to obtain maximum statistical power.

This work is supported by NASA ADP Grant 99I0055

The author(s) of this abstract have provided an email address for comments about the abstract: phillips@friday.gsfc.nasa.gov

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