Revisiting the screening mechanism in $f(R)$ gravity

Abstract

We reexamine the screening mechanism in $f(R)$ gravity using N-body simulations. By explicitly examining the relation between the extra scalar field $\hat{I}´f_R$ and the gravitational potential $\ddot{I}•$ in the perturbed Universe, we find that the relation between these two fields plays an important role in understanding the screening mechanism. We show that the screening mechanism in $f(R)$ gravity depends mainly on the depth of the potential well, and find a useful condition for identifying unscreened halos in simulations. We also discuss the potential application of our results to real galaxy surveys.

16 pages, 13 figures, revised version, accepted for publication in PRD