Constraints on shear and rotation with massive galaxy clusters

Understand

A precise determination of the mass function is an important tool to verify cosmological predictions of the $\Lambda$CDM model and to infer more precisely the better model describing the evolution of the Universe.

• Galaxy clusters have been currently used to infer cosmological parameters, in particular the matter density parameter $\Omega_{\rm m}$, the matter power spectrum normalization $\sigma_8$ and the equation of state parameter $w_{\rm de}$ of the dark energy fluid.
• In this work, using data on massive galaxy clusters ($M>8\times 10^{14}~h^{-1}~M_{\odot}$) in the redshift range $0.05\lesssim z\lesssim 0.83$ we put constraints on the parameter $\alpha$ introduced within the formalism of the extended spherical collapse model to quantify deviations from sphericity due to shear and rotation.
• Since at the moment there is no physical model describing its functional shape, we assume it to be a logarithmic function of the cluster mass.