In kinetically coupled vector inflation, the bispectrum in the large-h regime exhibits competing local and flattened non-Gaussian signals with distinct h scalings that distinguish vector-supported dynamics.
The shape of primordial non-Gaussianity and the CMB bispectrum
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
We present a set of formalisms for comparing, evolving and constraining primordial non-Gaussian models through the CMB bispectrum. We describe improved methods for efficient computation of the full CMB bispectrum for any general (non-separable) primordial bispectrum, incorporating a flat sky approximation and a new cubic interpolation. We review all the primordial non-Gaussian models in the present literature and calculate the CMB bispectrum up to l <2000 for each different model. This allows us to determine the observational independence of these models by calculating the cross-correlation of their CMB bispectra. We are able to identify several distinct classes of primordial shapes - including equilateral, local, warm, flat and feature (non-scale invariant) - which should be distinguishable given a significant detection of CMB non-Gaussianity. We demonstrate that a simple shape correlator provides a fast and reliable method for determining whether or not CMB shapes are well correlated. We use an eigenmode decomposition of the primordial shape to characterise and understand model independence. Finally, we advocate a standardised normalisation method for $f_{NL}$ based on the shape autocorrelator, so that observational limits and errors can be consistently compared for different models.
citation-role summary
citation-polarity summary
fields
hep-th 2verdicts
UNVERDICTED 2roles
background 1polarities
background 1representative citing papers
In dynamical Chern-Simons inflation the parity-odd trispectrum is a double copy of the mixed bispectrum and parity-odd power spectrum via a prior factorization formula.
citing papers explorer
-
Inflation with vector fields revisited: non-Gaussianities
In kinetically coupled vector inflation, the bispectrum in the large-h regime exhibits competing local and flattened non-Gaussian signals with distinct h scalings that distinguish vector-supported dynamics.
-
A Match Made in Heaven: Linking Observables in Inflationary Cosmology
In dynamical Chern-Simons inflation the parity-odd trispectrum is a double copy of the mixed bispectrum and parity-odd power spectrum via a prior factorization formula.