2015/02/03 by Bekir Baytaş, Aruna Kesavan, Elliot Nelson +2 · 1 citation
Mathematics · Physics and Astronomy · #Astrophysics #Bicoherence #Bispectrum #COSMIC cancer database #Cosmic microwave background #Cosmic variance #Cosmology and Gravitation Theories #Equilateral triangle #Galaxies: Formation, Evolution, Phenomena #Gaussian #Geometry #Inflation (cosmology) #Mathematics #Non-Gaussianity #Physics #Quantum mechanics #Redshift #Scalar (mathematics) #Solar and Space Plasma Dynamics #Spectral density #Statistical physics #Statistics #Theoretical physics #Variance (accounting) #astro-ph.CO
paper · pdf · doi:10.1103/physrevd.91.083518
published as Phys. Rev. D 91, 083518 (2015) · 17 pages, 2 figures
arxiv created 2015/02/03 · openalex publication_date 2015/04/09 · arxiv updated 2015/04/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present examples of non-Gaussian statistics that can induce bispectra matching local and nonlocal (including equilateral) templates in biased subvolumes. We find cases where the biasing from coupling to long wavelength modes affects only the power spectrum, only the bispectrum or both. Our results suggest that ruling out multifield scenarios is quite difficult: some measurements of the scalar correlations, including the shape of the bispectrum, can be consistent with single-clock predictions even when cosmic variance from super-horizon modes is at work. Furthermore, if observations of the density perturbations rule out single-clock inflation, we will face a serious cosmic variance obstacle in drawing any further conclusions about the particle physics origin of the scalar fluctuations.