  We present a set of simulations of the macrolensing effects produced by
large-scale cosmological violations of the energy conditions. These simulations
show how the appearance of a background field of galaxies is affected when
lensed by a region with an energy density equivalent to a negative mass ranging
from $10^{12}$ to $10^{17}$ solar masses. We compare with the macrolensing
results of equal amounts of positive mass, and show that, contrary to the usual
case where tangential arc-like structures are expected, there appear radial
arcs-runaway filaments-and a central void. These results make the cosmological
macrolensing produced by space-time domains where the weak energy conditions is
violated, observationally distinguishable from standard regions. Whether large
domains with negative energy density indeed exist in the universe can now be
decided by future observations of deep fields.
