Detection of primordial non-Gaussianity fNL in the WMAP 3-year data at above 99.5% confidence - AstrophysicsReport as inadecuate




Detection of primordial non-Gaussianity fNL in the WMAP 3-year data at above 99.5% confidence - Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We present evidence for the detection of primordial non-Gaussianity of thelocal type fNL, using the temperature information of the Cosmic MicrowaveBackground CMB from the WMAP 3-year data. We employ the bispectrum estimatorof non-Gaussianity described in Yadav et al. 2007 which allows us to analyzethe entirety of the WMAP data without an arbitrary cut-off in angular scale.Using the combined information from WMAP-s two main science channels up tolmax=750 and the conservative Kp0 foreground mask we find 27 < fNL < 147 at 95%C.L., with a central value of fNL=87. This corresponds to a rejection of fNL=0at more than 99.5% significance. We find that this detection is robust tovariations in lmax, frequency and masks, and that no known foreground,instrument systematic, or secondary anisotropy explains our signal whilepassing our suite of tests. We explore the impact of several analysis choiceson the stated significance and find 2.5 sigma for the most conservative view.We conclude that the WMAP 3-year data disfavors canonical single fieldslow-roll inflation.



Author: Amit P. S. Yadav, Benjamin D. Wandelt

Source: https://arxiv.org/



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