Simulation of non-Gaussian CMB maps
ArXiv astro-ph/0406136 (2004)
Authors:
Graca Rocha, MP Hobson, Sarah Smith, Pedro Ferreira, Anthony Challinor
Abstract:
A simple method is presented for the rapid simulation of
statistically-isotropic non-Gaussian maps of CMB temperature fluctuations with
a given power spectrum and analytically-calculable bispectrum and higher-order
polyspectra. The $n$th-order correlators of the pixel values may also be
calculated analytically. The cumulants of the simulated map may be used to
obtain an expression for the probability density function of the pixel
temperatures. The statistical properties of the simulated map are determined by
the univariate non-Gaussian distribution from which pixel values are drawn
independently in the first stage of the simulation process. We illustrate the
method using a non-Gaussian distribution derived from the wavefunctions of the
harmonic oscillator. The basic simulation method is easily extended to produce
non-Gaussian maps with a given power spectrum and diagonal bispectrum.
