Primordial Non-Gaussianity and Bispectrum Measurements in the Cosmic Microwave Background and Large-Scale Structure

Figure 5

Orthonormal eigenmode decomposition coefficients (26) for the equilateral and DBI models (a) and shape correlations (19) of the original bispectrum against the partial sum up to a given mode (b). The correlation plot includes both primordial and late-time CMB bispectra for the equilateral and DBI models, as well as the late-time CMB bispectrum from cosmic strings (refer to Section 3). In all cases, we find that we need at most 15 three-dimensional modes to obtain a correlation greater than 98% (primordial convergence without the acoustic peaks requires only 6 modes).

(a)

(b)