  We investigate the restrictions on the equation-of-state parameter of phantom
cosmology, due to the minimum quantum gravitational requirements. We find that
for all the examined $w_\Lambda(z)$-parametrizations and for arbitrary phantom
potentials and spatial curvature, the phantom equation-of-state parameter is
not restricted at all. This is in radical contrast with the quintessence
paradigm, and makes phantom cosmology more robust and capable of constituting
the underlying mechanism for dark energy.
