English

Non-gaussian Features of Linear Cosmic String Models

Astrophysics 2009-10-30 v2

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(Ωh2)11.5{(\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 Λ\Lambda-universe with Γ=Ωh\lsim0.2\Gamma=\Omega h \lsim 0.2.

Keywords

Cite

@article{arxiv.astro-ph/9803120,
  title  = {Non-gaussian Features of Linear Cosmic String Models},
  author = {P. P. Avelino and E. P. S. Shellard and J. H. P. Wu and B. Allen},
  journal= {arXiv preprint arXiv:astro-ph/9803120},
  year   = {2009}
}

Comments

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

R2 v1 2026-07-22T09:38:54.764Z