We review the oscillator construction of the unitary representations o
f non-compact groups and supergroups and study the unitary supermultip
lets of OSp(1/32, R) in relation to M-theory. OSp(1/32, R) has a singl
eton supermultiplet consisting of a scalar and a spinor field. Parity
invariance leads us to consider OSp(1/32, R)(L) x OSp(1/32, R)(R) as t
he ''minimal'' generalized AdS supersymmetry algebra of M-theory corre
sponding to the embedding of two spinor representations of SO(10, 2) i
n the fundamental representation of Sp(32, R). The contraction to the
Poincare superalgebra with central charges proceeds via a diagonal sub
supergroup OSp(1/32, R)(L-R) which contains the common subgroup SO(10,
1) of the two SO(10,2) factors. The parity invariant singleton superm
ultiplet of OSp(1/32, R)(L) x OSp(1/32, R)(R) decomposes into an infin
ite set of ''doubleton'' supermultiplets of the diagonal OSp(1/32,R)(L
-R). There is a unique ''CPT self-conjugate'' doubleton supermultiplet
whose tensor product with itself yields the ''massless'' generalized
AdS(11) supermultiplets. The massless graviton supermultiplet contains
fields corresponding to those of eleven-dimensional supergravity plus
additional ones. Assuming that an AdS phase of M-theory exists we arg
ue that the doubleton field theory must be the holographic superconfor
mal field theory in ten dimensions that is dual to M-theory in the sam
e sense as the duality between the N = 4 super-Yang-Mills in d = 4 and
the IIB superstring over AdS(5) x S-5. (C) 1998 Elsevier Science B.V.