On the embedding of space-time symmetries into simple superalgebras

We explore the embedding of Spin groups of arbitrary dimension and signature into simple superalgebras in the case of extended supersymmetry. The R-symmetry, which generically is not compact, can be chosen compact for all the cases that are congruent mod 8 to the physical conformal algebra so(D − 2,2), D ≥ 3. An so(1,1) grading of the superalgebra is found in all cases. Central extensions of super translation algebras are studied within this framework