osp(1|32) and extensions of super-AdS5×S5 algebra Original Research Article

The super-AdS5×S5 and the four-dimensional N=4 superconformal algebras play important roles in superstring theories. It is often discussed the roles of the osp(1|32) algebra as a maximal extension of the superalgebras in flat background. In this paper we show that the su(2,2|4), the super-AdS5×S5 algebra or the superconformal algebra, is not a restriction of the osp(1|32) though the bosonic part of the former is a subgroup of the latter. There exist only two types of u(1) extension of the super-AdS5×S5 algebra if the bosonic AdS5×S5 covariance is imposed. Possible significance of the results is also discussed briefly.