Galactic sparsity and $\Lambda$-gravity
  The sparsity parameter for clusters of galaxies is obtained in the context of
$\Lambda$-gravity. It is shown that, the theoretical estimated values are
within the reported error limits of the measured data. Thus, in the future the
sparsity parameter can serve as an informative new test to detect the
discrepancy between General Relativity and $\Lambda$-gravity.
