The fundamental question addressed in this Letter is whether or not the partial Chapman–Enskog expansion $P_{xy}=-\sum _{k=0}^{\infty }{\eta }_k(\partial u_x/\partial y{)}^{2k+1}$ of the shear stress converges for a gas of inelastic hard spheres. By using a simple kinetic model it is shown that, in contrast to the elastic case, the above series does converge, the radius of convergence increasing with inelasticity. It is argued that this paradoxical conclusion is not an artifact of the kinetic model and can be understood in terms of the time evolution of the scaled shear rate in the uniform shear flow.

• Received 21 November 2007

DOI:https://doi.org/10.1103/PhysRevLett.100.078003