Spherical collapse model and cluster number counts in power law $f(T)$ gravity

TL;DR

This paper investigates how a specific power law $f(T)$ gravity model influences the spherical collapse process and the resulting cluster counts, providing potential observational tests to distinguish it from standard $\\Lambda$CDM cosmology.

Contribution

It introduces the spherical collapse model within a power law $f(T)$ gravity framework and predicts cluster counts that differ from $\\Lambda$CDM, highlighting the impact of the parameter $b$.

Findings

Positive $b$ predicts more virialized halos than $\\Lambda$CDM.

Negative $b$ predicts fewer virialized halos than $\\Lambda$CDM.

Growth of overdensities is affected by the power-law parameter $b$.

Abstract

We study the spherical collapse model (SCM) in the framework of spatially flat power law $f(T) \propto (-T)^{b}$ gravity model. We find that the linear and non-linear growth of spherical overdensities of this particular $f(T)$ model are affected by the power-law parameter $b$. Finally, we compute the predicted number counts of virialized haloes in order to distinguish the current $f(T)$ model from the expectations of the concordance $\Lambda$ cosmology. Specifically, the present analysis suggests that the $f(T)$ gravity model with positive (negative) $b$ predicts more (less) virialized objects with respect to those of $\Lambda$CDM.