A highly non-Gaussian cosmological perturbation with a flat spectrum has unusual stochastic properties. We show that they depend on the size of the box within which the perturbation is defined, but that for a typical observer the parameters defining the perturbation "run" to compensate for any change in the box size. Focusing on the primordial curvature perturbation, we show that an uncorrelated Gaussian-squared component is bounded at around the 10% level by the Wilkinson Microwave Anisotropy Probe (WMAP) bound on the bispectrum, and we show that a competitive bound may follow from the trispectrum when it too is bounded by WMAP. Similar considerations apply to a highly non-Gaussian isocurvature perturbation.
|Número de artículo
|Physical Review D - Particles, Fields, Gravitation and Cosmology
|Publicada - 15 ene. 2006
|Publicado de forma externa