  Considering a granular fluid of inelastic smooth hard spheres we discuss the
conditions delineating the rheological regimes comprising Newtonian,
Bagnoldian, shear thinning, and shear thickening behavior. Developing a kinetic
theory, valid at finite shear rates and densities around the glass transition
density, we predict the viscosity and Bagnold coefficient at practically
relevant values of the control parameters. The determination of full flow
curves relating the shear stress $\sigma$ to the shear rate $\dot\gamma$, and
predictions of the yield stress complete our discussion of granular rheology
derived from first principles.
