  We briefly review our works for graviton and spherical graviton potentials in
a plane-wave matrix model. To compute them, it is necessary to devise a
configuration of the graviton solutions, since the plane-wave matrix model
includes mass terms and hence the gravitons are not free particles as in the
BFSS matrix model but harmonic oscillators or rotating particles. The
configuration we proposed consists of a rotating graviton and an elliptically
rotating graviton. It is applied to the two-body interaction of spherical
gravitons in the SO(6) symmetric space, and then to that of point-like
gravitons in the SO(3) symmetric space. In both cases the leading term of the
resulting potential is 1/r^7. This result strongly suggests that the potentials
should be closely related to the light-front eleven-dimensional supergravity
linearized around the pp-wave background.
