CMB constraints on running non-Gaussianity

Abstract

We develop a complete set of tools for CMB forecasting, simulation and estimation of primordial running bispectra, arising from a variety of curvaton and single-field (DBI) models of Inflation. We validate our pipeline using mock CMB running non-Gaussianity realizations and test it on real data by obtaining experimental constraints on the f_NL running spectral index, n_NG, using WMAP 9-year data. Our final bounds (68% C.L.) read -0.6< n_NG<1.4}, -0.3< n_NG<1.2, -1.1<n_NG<0.7 for the single-field curvaton, two-field curvaton and DBI scenarios, respectively. We show forecasts and discuss potential improvements on these bounds, using Planck and future CMB surveys.