  We study heat conduction in one-dimensional granular gases. In particular, we
consider two mechanisms of viscous dissipation during inter-grain collisions.
In one, the dissipative force is proportional to the grain's velocity and
dissipates not only energy but also momentum. In the other, the dissipative
force is proportional to the relative velocity of the grains and therefore
conserves momentum even while dissipating energy. This allows us to explore the
role of momentum conservation in the heat conduction properties of this
one-dimensional nonlinear system. We find normal thermal conduction whether or
not momentum is conserved.
