Supersymmetric branes in the matrix model of a pp wave background -: art. no. 045017

We consider the matrix model associated with a pp-wave background and construct supersymmetric branes. In addition to the spherical membrane preserving 16 supersymmetries, one may construct rotating elliptic membranes preserving 8 supersymmetries. The other branch describes rotating 1/8 BPS hyperbolic branes in general. When the angular momentum vanishes, the hyperbolic brane becomes 1/4 Bogomol'nyi-Prasad-Sommerfield (BPS) preserving 8 real supersymmetries. It may have the shape of a hyperboloid of one or two sheets embedded in the flat three space. We study the spectrum of the worldvolume fields on the hyperbolic branes and show that there are no massless degrees. We also compute the spectrum of the 0-2 strings.