We review the oscillator construction of the unitary representations of
noncompact groups and supergroups and study the unitary supermultiplets of
OSp(1/32,R) in relation to M-theory. OSp(1/32,R) has a singleton 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 the "minimal" generalized AdS
supersymmetry algebra of M-theory corresponding to the embedding of two spinor
representations of SO(10,2) in the fundamental representation of Sp(32,R). The
contraction to the Poincare superalgebra with central charges proceeds via a
diagonal subsupergroup 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
supermultiplet of OSp(1/32,R)_L \times OSp(1/32,R)_R decomposes into an
infinite 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 11-dimensional supergravity plus
additional ones. Assuming that an AdS phase of M-theory exists we argue that
the doubleton field theory must be the holographic superconformal field theory
in ten dimensions that is dual to M-theory in the same sense as the duality
between the N=4 super Yang-Mills in d=4 and the IIB superstring over AdS_5 X
S^5.Comment: 25 pages, LaTex ; footnotes 5 and 6 modified and 3 new references
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