We show how , the radial location of the minimum of the
differential radial mass profile of a galaxy cluster, can probe
the theory of gravity. We derive of the dark matter halos of
galaxy clusters from N-body cosmological simulations that implement two
different theories of gravity: standard gravity in the CDM model and
. We extract 49169 dark matter halos in 11 redshift bins in the range
and in three different mass bins in the range
$0.9