  We investigate the gauge/gravity duality in the interaction between two
spherical membranes in the 11-dimensional pp-wave background. On the
supergravity side, we find the solution to the field equations at locations
close to a spherical source membrane, and use it to obtain the light cone
Lagrangian of a spherical probe membrane very close to the source, i.e., with
their separation much smaller than their radii. On the gauge theory side, using
the BMN matrix model, we compute the one-loop effective potential between two
membrane fuzzy spheres. Perfect agreement is found between the two sides.
Moreover, the one-loop effective potential we obtain on the gauge theory side
is valid beyond the small-separation approximation, giving the full
interpolation between interactions of membrane-like objects and that of
graviton-like objects.
