Constraining Primordial Non-Gaussianities from the WMAP2 2-1 Cumulant Correlator Power Spectrum

Abstract

We measure the 2-1 cumulant correlator power spectrum $C_l^{21}$, a degenerate bispectrum, from the second data release of the Wilkinson Microwave Anisotropy Probe (WMAP). Our high resolution measurements with SpICE span a large configuration space ($\simeq 168\times 999$) corresponding to the possible cross-correlations of the maps recorded by the different differencing assemblies. We present a novel method to recover the eigenmodes of the correspondingly large Monte Carlo covariance matrix. We examine its eigenvalue spectrum and use random matrix theory to show that the off diagonal terms are dominated by noise. We minimize the ${\chi }^2$ to obtain constraints for the non-linear coupling parameter $f_{NL}=22\pm 52(1\sigma )$.

4 pages,2 figures; typos corrected, references changed

Cited by in corpus (5)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Effects of Scale-Dependent Non-Gaussianity on Cosmological Structures
• Fast Estimator of Primordial Non-Gaussianity from Temperature and Polarization Anisotropies in the Cosmic Microwave Background
• Shrinkage Estimation of the Power Spectrum Covariance Matrix
• The trispectrum of 21-cm background anisotropies as a probe of primordial non-Gaussianity