  Rheology of a dilute cohesive granular gas is theoretically and numerically
studied. The flow curve between the shear viscosity and the shear rate is
derived from the inelastic Boltzmann equation for particles having square-well
potentials in a simple shear flow. It is found that (i) the stable uniformly
sheared state only exists above a critical shear rate and (ii) the viscosity in
the uniformly sheared flow is almost identical to that for uniformly sheared
flow of hard core granular particles. Below the critical shear rate, clusters
grow with time, in which the viscosity can be approximated by that for the
hard-core fluids if we replace the diameter of the particle by the mean
diameter of clusters.
