  We describe the robustness of an excitonic condensate in double layer
graphene against layer density fluctuations and the associated charge
inhomogeneity, and discuss the implications for observing the condensate under
current experimental conditions. We solve the mean-field equations for a finite
imbalance in the Fermi energies in each layer and utilize the results in two
phenomenological models for inhomogeneity. We find that the stability of the
excitonic condensate against density fluctuations is strongly dependent on the
size of the excitonic gap, and that transport experiments (such as Coulomb
drag) which rely on percolation of the exciton current through the
inhomogeneous sample are promising methods for observing the condensate.
