2012/11/01 by Jerome Martin, Jérôme Martin, Hayato Motohashi +1 · 351 citations
Mathematics · Physics and Astronomy · #Bispectrum #Black Holes and Theoretical Physics #CMB cold spot #Computer science #Consistency (knowledge bases) #Cosmic microwave background #Cosmology and Gravitation Theories #Econometrics #Galaxies: Formation, Evolution, Phenomena #Inflation (cosmology) #Mathematics #Non-Gaussianity #Physics #Quantum mechanics #Relation (database) #Spectral density #Statistical physics #Statistics #Theoretical physics #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.87.023514
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 87(2) (American Physical Society) · 11 pages, 6 figures
arxiv created 2012/11/01 · openalex publication_date 2013/01/22 · arxiv updated 2013/05/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Ultra slow-roll inflation has recently been used to challenge the non-Gaussianity consistency relation. We show that this inflationary scenario belongs to a one-parameter class of models, and we study its properties and observational predictions. We demonstrate that the power spectrum remains scale invariant and that the bispectrum is of the local type with fNL=5(3\ensuremath-ns)/4, which indeed represents a modification of the consistency relation. However, we also show that the system is unstable and suffers from many physical problems among which is the difficulty in correctly WMAP normalizing the model. We conclude that ultra slow-roll inflation remains a very peculiar case, the physical relevance of which is probably not sufficient to call into question the validity of the consistency relation.