CMB contraints on primordial non-Gaussianity from the bispectrum (f(NL)) and trispectrum (g(NL) and tau(NL)) and a new consistency test of single-field inflation
Smidt, Joseph
Smidt
Joseph
Amblard, Alexandre
Amblard
Alexandre
Byrnes, Christian
Byrnes
Christian
Cooray, Asantha
Cooray
Asantha
Heavens, Alan
Heavens
Alan
Munshi, Dipak
Munshi
Dipak
We outline the expected constraints on non-Gaussianity from the cosmic microwave background with current and future experiments, focusing on both the third (f(NL)) and fourth-order (g(NL) and tau(NL)) amplitudes of the local configuration or non-Gaussianity. The experimental focus is the skewness (two-to-one) and kurtosis (two-to-two and three-to-one) power spectra from weighted maps. In addition to a measurement of tau(NL) and g(NL) with WMAP 5-year data, our study provides the first forecasts for future constraints on g(NL). We describe how these statistics can be corrected for the mask and cut-sky through a window function, bypassing the need to compute linear terms that were introduced for the previous-generation non-Gaussianity statistics, such as the skewness estimator. We discus the ratio A(NL) = tau(NL)/(6f(NL)/5)(2) as an additional test of single-field inflationary models and discuss the physical significance of each statistic. Using these estimators with WMAP 5-Year V + W-band data out to l(max) = 600 we constrain the cubic order non-Gaussianity parameters tau(NL), and g(NL) and find -7.4 < g(NL)/10(5) < 8.2 and -0.6 < tau(NL)/10(4) < 3.3 improving the previous COBE-based limit on tau(NL) < 10(8) nearly 4 orders of magnitude with WMAP.
81
12
American Physical Society (APS)
2010