The spectrum of the S⁵ compactification of the chiral N=2, D=10 supergravity and the unitary supermultiplets of U(2,2/4)

The authors calculate the spectrum of the S⁵ compactification of the chiral N=2, D=10 supergravity theory. The modes on S⁵ fall into unitary irreducible representations of the D=5, N=8 anti-de Sitter supergroup U(2,2/4). These unitary supermultiplets involve field of spin <or=2 with quantised 'mass' eigenvalues. The massless multiplet contains fifteen vector fields, six self-dual and six anti-self-dual anti-symmetric tensor fields. The fields of the massless multiplet are expected to be those of a gauged N=8 theory in D=5 with a local gauge group SU(4).