Primordial non-Gaussianities in the intergalactic medium |
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Authors: | M Viel E Branchini K Dolag M Grossi S Matarrese L Moscardini |
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Institution: | INAF –Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, I-34131 Trieste, Italy;INFN/National Institute for Nuclear Physics, Via Valerio 2, I-34127 Trieste, Italy;Dipartimento di Fisica, Universitàdi Roma TRE, Via della Vasca Navale 84, I-00146 Roma, Italy;Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild Strasse 1, D-85748 Garching, Germany;Dipartimento di Fisica, Universitàdi Padova, Via Marzolo 8, I-35131 Padova, Italy;INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padova, Italy;Dipartimento di Astronomia, Universitàdi Bologna, Via Ranzani 1, I-40127 Bologna, Italy;INFN, Sezione di Bologna, viale Berti Pichat 6/2, I-40127 Bologna, Italy |
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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-α flux in the high-redshift intergalactic medium. Imprints of non-Gaussianity are present and are larger at high redshifts. Differences larger than 20 per cent 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=±100 when compared to a standard Λ cold dark matter cosmology with f NL= 0 . We also investigate the one-dimensional flux bispectrum: at the largest scales (corresponding to tens of Mpc), we expect deviations in the flux bispectrum up to 20 per cent at z ∼ 4 (for f NL=±100 ), significantly larger than deviations of ∼3 per cent 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-α forest could be possible with future data sets. |
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Keywords: | quasars: absorption lines cosmology: observations cosmology: theory |
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