TY - JOUR
T1 - Nonlocal bispectra from super cosmic variance
AU - Baytaş, Bekir
AU - Kesavan, Aruna
AU - Nelson, Elliot
AU - Park, Sohyun
AU - Shandera, Sarah
N1 - Publisher Copyright:
© 2015 American Physical Society.
PY - 2015/4/9
Y1 - 2015/4/9
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevD.91.083518
DO - 10.1103/PhysRevD.91.083518
M3 - Article
AN - SCOPUS:84929206707
SN - 1550-7998
VL - 91
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 8
M1 - 083518
ER -