The cluster abundance in cosmic string models for structure formation
Journal
Monthly Notices of the Royal Astronomical Society
Journal Volume
318
Journal Issue
2
Pages
329-332
Date Issued
2000
Author(s)
Abstract
We use the present observed number density of large X-ray clusters to constrain the amplitude of matter density perturbations induced by cosmic strings on the scale of 8 h-1 Mpc (σ8), in both open cosmologies and flat models with a non-zero cosmological constant. We find a slightly lower value of σ8 than that obtained in the context of primordial Gaussian fluctuations generated during inflation. This lower normalization of σ8 results from the mild non-Gaussianity on cluster scales, where the one-point probability distribution function is well approximated by a χ2 distribution and thus has a longer tail than a Gaussian distribution. We also show that σ8 normalized using cluster abundance is consistent with the COBE normalization.
SDGs
Type
journal article