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arXiv · 0811.2223

Primordial non-Gaussianities in the Intergalactic Medium

M. Viel·E. Branchini·K. Dolag·M. Grossi·S. Matarrese·L. Moscardini
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Abstract

We present results from the first high-resolution hydrodynamical simulations of non-Gaussian cosmological models. We focus on the statistical properties of the transmitted Lyman-alpha flux in the high redshift intergalactic medium. Imprints of non-Gaussianity are present and are larger at high redshifts. Differences larger than 20 % at z>3 in the flux probability distribution function for high transmissivity regions (voids) are expected for values of the non linearity parameter f_NL=\pm 100 when compared to a standard LCDM cosmology with f_NL=0. We investigate also the one-dimensional flux bispectrum: at the largest scales (corresponding to tens of Mpc) we expect deviations in the flux bispectrum up to 20% at z~4 (for f_NL=\pm 100), significantly larger than deviations of ~ 3% in the flux power spectrum. We briefly discuss possible systematic errors that can contaminate the signal. Although challenging, a detection of non-Gaussianities in the interesting regime of scales and redshifts probed by the Lyman-alpha forest, could be possible with future data sets.

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M. Viel, E. Branchini, K. Dolag, M. Grossi, S. Matarrese, L. Moscardini. 2008-11-13. Primordial non-Gaussianities in the Intergalactic Medium. https://doi.org/10.1111/j.1365-2966.2008.14236.x

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