Non-gaussian Features of Linear Cosmic String Models

Abstract

We investigate the non-gaussian properties of cosmic-string-seeded linear density perturbations with cold and hot dark matter backgrounds, using high-resolution numerical simulations. We compute the one-point probability density function of the resulting density field, its skewness, kurtosis, and genus curves for different smoothing scales. A semi-analytic model is then invoked to provide a physical interpretation of our results. We conclude that on scales smaller than $1.5{(\Omega h^2)}^{-1}$Mpc, perturbations seeded by cosmic strings are very non-gaussian. These scales may still be in a linear or mildly non-linear regime in an open or $\Lambda$-universe with $Γ=Ωh \lsim 0.2$.

6 pages, 6 figures; accepted by Ap. J. Lett. With error bars included in the genus curves (figure 3). Also corrected for a minor error in the standard normalization of wavenumbers $k$, resulting from using an incorrect figure for the time $t_{eq}$ of the equal matter-radiation transition given in the Kolb and Turner textbook "The Early Universe". Main conclusions remain unchanged

References in corpus (3)

• Structure formation by cosmic strings with a cosmological constant
• Cosmic-String-Seeded Structure Formation
• The Peculiar-Velocity-Field in Structure Formation Theories with Cosmic Strings

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