Vertex operators for the supermembrane

We derive the vertex operators that are expected to govern the emission of the massless d = 11 supermultiplet from the supermembrane in the light cone gauge. We demonstrate that they form a representation of the supersymmetry algebra and reduce to the type-IIA superstring vertex operators under doub le-dimensional reduction, as well as to the vertices of the d = 11 superpar ticle in the point-particle limit. As a byproduct, our results can be used to derive the corresponding vertex operators for matrix theory and to descr ibe its linear coupling to an arbitrary d = 11 supergravity background. Pos sible applications are discussed.