CMB constraints on running non-Gaussianity

TL;DR

This paper develops tools for analyzing primordial running non-Gaussianity in the CMB, validates them with simulations, and applies them to WMAP data to constrain the running spectral index across different inflation models.

Contribution

It introduces a comprehensive pipeline for forecasting, simulating, and estimating running bispectra in the CMB, and provides the first experimental constraints on the running spectral index for multiple inflation scenarios.

Findings

Constraints on $n_{NG}$ from WMAP data for different models.

Validated pipeline with mock realizations.

Forecasts for future CMB surveys like Planck.

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 $f_{\rm NL}$ running spectral index, $n_{\rm NG}$, using WMAP 9-year data. Our final bounds (68\% C.L.) read $-0.6< n_{\rm NG}<1.4$, $-0.3< n_{\rm NG}<1.2$, $-1.1<n_{\rm NG}<0.7$ for the single-field curvaton, two-field curvaton and DBI scenarios, respectively. We show forecasts and discuss potential improvements on these bounds, using {\it Planck} and future CMB surveys.