  Rheological properties of a dense granular material consisting of
frictionless spheres are investigated. It is found that the shear stress, the
pressure, and the kinetic temperature obey critical scaling near the jamming
transition point, which is considered as a critical point. These scaling laws
have some peculiar properties in view of conventional critical phenomena
because the exponents depend on the interparticle force models so that they are
not universal. It is also found that these scaling laws imply the relation
between the exponents that describe the growing correlation length.
