TY - JOUR
T1 - Non-gaussian mode coupling and the statistical cosmological principle
AU - Loverde, Marilena
AU - Nelson, Elliot
AU - Shandera, Sarah
PY - 2013/6
Y1 - 2013/6
N2 - Local-type primordial non-Gaussianity couples statistics of the curvature perturbation ζ on vastly different physical scales. Because of this coupling, statistics (i.e. the polyspectra) of ζ in our Hubble volume may not be representative of those in the larger universe - that is, they may be biased. The bias depends on the local background value of ζ, which includes contributions from all modes with wavelength k ≲ H0 and is therefore enhanced if the entire post-inflationary patch is large compared with our Hubble volume. We study the bias to locally-measured statistics for general local-type non-Gaussianity. We consider three examples in detail: (i) the usual fNL, gNL model, (ii) a strongly non-Gaussian model with ζ ∼ ζpG, and (iii) two-field non-Gaussian initial conditions. In each scenario one may generate statistics in a Hubble-size patch that are weakly Gaussian and consistent with observations despite the fact that the statistics in the larger, post-inflationary patch look very different.
AB - Local-type primordial non-Gaussianity couples statistics of the curvature perturbation ζ on vastly different physical scales. Because of this coupling, statistics (i.e. the polyspectra) of ζ in our Hubble volume may not be representative of those in the larger universe - that is, they may be biased. The bias depends on the local background value of ζ, which includes contributions from all modes with wavelength k ≲ H0 and is therefore enhanced if the entire post-inflationary patch is large compared with our Hubble volume. We study the bias to locally-measured statistics for general local-type non-Gaussianity. We consider three examples in detail: (i) the usual fNL, gNL model, (ii) a strongly non-Gaussian model with ζ ∼ ζpG, and (iii) two-field non-Gaussian initial conditions. In each scenario one may generate statistics in a Hubble-size patch that are weakly Gaussian and consistent with observations despite the fact that the statistics in the larger, post-inflationary patch look very different.
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U2 - 10.1088/1475-7516/2013/06/024
DO - 10.1088/1475-7516/2013/06/024
M3 - Article
AN - SCOPUS:84880686856
SN - 1475-7516
VL - 2013
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
IS - 6
M1 - 024
ER -