2006/11/30 by Christian T. Byrnes, Misao Sasaki, David Wands · 5 citations
Mathematics · Physics and Astronomy · #Astrophysics #Bispectrum #Black Holes and Theoretical Physics #Cosmic microwave background #Cosmological perturbation theory #Cosmology #Cosmology and Gravitation Theories #Dark energy #Field (mathematics) #Formalism (music) #Galaxies: Formation, Evolution, Phenomena #Hubble's law #Inflation (cosmology) #Mathematics #Non-Gaussianity #Physics #Quantum mechanics #Spectral density #Statistical physics #Theoretical physics #Trispectrum #astro-ph
paper · pdf · doi:10.1103/physrevd.74.123519
published as Phys.Rev.D74:123519,2006 · 9 pages, no figures, v2: references added, minor changes, matches version to be published in Phys. Rev. D
arxiv created 2006/12/21 · openalex publication_date 2006/12/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We use the \ensuremathδN formalism to describe the leading order contributions to the primordial power spectrum, bispectrum, and trispectrum in multiple-field models of inflation at leading order in a perturbative expansion. In slow-roll models where the initial field fluctuations at Hubble exit are nearly Gaussian, any detectable non-Gaussianity is expected to come from super-Hubble evolution. We show that the contribution to the primordial trispectrum can be described by two nonlinearity parameters, \ensuremathτNL and gNL, which are dependent upon the second and third derivatives of the local expansion with respect to the field values during inflation.