Momentum dependence of the bispectrum in two-field inflation

Abstract

We examine the momentum dependence of the bispectrum of two-field inflationary models within the long-wavelength formalism. We determine the sources of scale dependence in the expression for the parameter of non-Gaussianity fNL and study two types of variation of the momentum triangle: changing its size and changing its shape. We introduce two spectral indices that quantify the possible types of momentum dependence of the local type fNL and illustrate our results with examples.

23 pages, 16 figures. v2: Final version. Minor textual changes

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Cited by in corpus (6)

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• Scale-dependent bias from multiple-field inflation
• Scale and shape dependent non-Gaussianity in the presence of inflationary vector fields
• Non-Gaussianity in two-field inflation beyond the slow-roll approximation
• Covariant second-order perturbations in generalized two-field inflation
• Non-Gaussianity in Cosmology: from Inflation to the CMB