A Simultaneous Constraint on the Amplitude and Gaussianity of Mass Fluctuations in the Universe

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dc.creatorRobinson, James
dc.creatorGawiser, Eric
dc.creatorSilk, Joseph
dc.date1998-05-13
dc.date.accessioned2026-07-07T02:26:55Z
dc.date.available2026-07-07T02:26:55Z
dc.descriptionWe consider constraints on the amplitude of mass fluctuations in the universe, sigma_8, derived from two simple observations: the present number density of clusters and the amplitude of their correlation function. Allowing for the possibility that the primordial fluctuations are non-gaussian introduces a degeneracy in the value of sigma_8 preferred by each of these constraints. However, when the constraints are taken together this degeneracy is broken, yielding a precise determination of sigma_8 and the degree of non-gaussianity for a given background cosmology. For a flat, Omega_m=1 universe with a power spectrum parameterized by a CDM shape parameter Gamma=0.2, we find that the perturbations are consistent with a gaussian distribution with sigma_8=0.49(+0.08-0.07) (95% limits). For some popular choices of background model, including the favored low matter density models, the hypothesis that the primordial fluctuations are gaussian is ruled out with a high degree of confidence.
dc.descriptionSix pages including 3 postscript figures, submitted to Astrophysical Journal Letters
dc.identifierhttps://arxiv.org/abs/astro-ph/9805181
dc.identifierhttp://arxiv.org/abs/astro-ph/9805181
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/12471
dc.subjectAstrophysics
dc.titleA Simultaneous Constraint on the Amplitude and Gaussianity of Mass Fluctuations in the Universe
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