  Exclusion zones in the cross-correlations between critical points (peak-void,
peak-wall, filament-wall, filament-void) of the density field define
quasi-standard rulers that can be used to constrain dark matter and dark energy
cosmological parameters. The average size of the exclusion zone is found to
scale linearly with the typical distance between extrema. The latter changes as
a function of the matter content of the universe in a predictable manner, but
its comoving size remains essentially constant in the linear regime of
structure growth on large scales, unless the incorrect cosmology is assumed in
the redshift-distance relation. This can be used to constrain the dark energy
parameters when considering a survey that scans a range of redshifts. The
precision of the parameter estimation is assessed using a set of cosmological
simulations, and is found to be a 4$\sigma$ detection of a change in matter
content of 5%, or about 3.8$\sigma$ detection of 50% shift in the dark energy
parameter using a full sky survey up to redshift 0.5.
