Cosmic-String-Seeded Structure Formation

Abstract

We describe the results of high-resolution numerical simulations of string-induced structure formation in open universes and those with a non-zero cosmological constant. For models with $Γ= Ωh = 0.1 - 0.2$ and a cold dark matter background, we show that the linear density fluctuation power spectrum has both an amplitude at $8 h^{-1} Mpc, σ_8$, and an overall shape which are consistent within uncertainties with those currently inferred from galaxy surveys. The cosmic string scenario with hot dark matter requires a strongly scale-dependent bias in order to agree with observations.

5 pages, 3 figures; to appear in Phys. Rev. Lett. (Sept. 1998). With a cosmological constant included in the evolution equation (1), and simulations carried out accordingly. This verifies the accuracy of the extrapolation scheme for $Λ$-models taken previously. 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