The cluster abundance in cosmic string models for structure formation

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 $8h^{-1}$Mpc (${\sigma }_8$), in both open cosmologies and flat models with a non-zero cosmological constant. We find a slightly lower value of ${\sigma }_8$ than that obtained in the context of primordial Gaussian fluctuations generated during inflation. This lower normalization of ${\sigma }_8$ results from the mild non-Gaussianity on cluster scales, where the one point probability distribution function is well approximated by a ${\chi }^2$ distribution. We use our estimate of ${\sigma }_8$ to constrain the string linear energy density $\mu$ and show that it is consistent with the COBE normalization.

5 pages, 2 figures

References in corpus (3)

• Starburst galaxies and structure in the submillimetre background towards the Hubble Deep Field
• Evolution of the cluster abundance in non-Gaussian models
• Probing a regular orbit with spectral dynamics

Cited by in corpus (4)

• Cold gas and star formation in a merging galaxy sequence
• Primordial black hole constraints on non-gaussian inflation models
• Galaxy-QSO Correlation induced by Weak Gravitational Lensing arising from Large-Scale Structure
• Cluster abundance and large scale structure