Non-Gaussian temperature fluctuations in the cosmic microwave background sky from a random Gaussian density field

Abstract

view Abstract Citations (45) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Non-Gaussian Temperature Fluctuations in the Cosmic Microwave Background Sky from a Random Gaussian Density Field Scaramella, Roberto ; Vittorio, Nicola Abstract We point out that the cosmic microwave background (CMB) temperature fluctuations, observed in the microwave sky with a large antenna beam, may not be Gaussian distributed, even if the primordial matter density fluctuations constitute a random Gaussian field. This effect is due to a dominance of low-order multi-poles of the CMB anisotropy pattern and is then relevant for galaxy formation models with large-scale power, which produce CMB angular anisotropies through the familiar Sachs-Wolfe effect. We focus on the most popular case of a flat universe with scale- invariant, Gaussian distributed density fluctuations. In this case 30% of the cosmic observers would reject the hypothesis that CMB temperature fluctuations in their own microwave sky are Gaussian distributed at least at the 99% confidence level. We also give numerical bounds, at the 95% confidence level, for the skewness and kurtosis of the sky pixel temperature fluctuation distribution: these bounds will possibly be useful in discriminating against scenarios with primordial, Gaussian density fluctuations. Publication: The Astrophysical Journal Pub Date: July 1991 DOI: 10.1086/170205 Bibcode: 1991ApJ...375..439S Keywords: Normal Density Functions; Relic Radiation; Temperature Distribution; Distribution Functions; Galactic Clusters; Random Processes; Statistical Distributions; Space Radiation; COSMIC BACKGROUND RADIATION; GALAXIES: CLUSTERING full text sources ADS |