S-Z Power Spectra

TL;DR

This paper compares the Sunyaev-Zeldovich (S-Z) power spectra predictions across the standard LambdaCDM model and two alternative models with higher cluster abundance, to evaluate their consistency with observed CMB anisotropy data.

Contribution

It calculates and compares S-Z power spectra in the standard, non-Gaussian, and early dark energy models, highlighting differences and observational implications.

Findings

Higher S-Z power in alternative models matches observed high-multipole CMB anisotropy.

Standard model predicts lower S-Z power than observed.

Alternative models can be tested with future measurements of cluster abundance and S-Z anisotropy.

Abstract

There is some observational evidence for earlier evolution of clusters of galaxies than predicted in the standard LambdaCDM model with a Gaussian primordial density fluctuation field, and a low value for the mass variance parameter sigma_8. Particularly difficult in this model is the interpretation of possible excess CMB anisotropy on cluster scales as due to the Sunyaev-Zeldovich (S-Z) effect. We have calculated S-Z power spectra in the standard model, and in two alternative models which predict higher cluster abundance - a model with non-Gaussian PDF, and an early dark energy model. As anticipated, the levels of S-Z power in the latter two models are significantly higher than in the standard model, and in good agreement with current measurements of CMB anisotropy at high multipole values. Our results provide a sufficient basis for testing the viability of the three models by futur high quality measurements of cluster abundance and the anisotropy induced by the S-Z effect.