Glueball Spectrum for QCD from AdS Supergravity Duality

We present the analysis of the complete glueball spectrum for the $Ad{S}^7$ black hole supergravity dual of $QC{D}_4$ in strong coupling limit: $g^2 N \to \infty$. The bosonic fields in the supergravity multiplet lead to 6 independent wave equations contributing to glueball states with $J^{PC} = 2^{++},1^{±}, 1^{–}$,$0^{++}$and$0^{-+}$. We study the spectral splitting and degeneracy patterns for both $QC{D}_4$ and $QC{D}_3$. Despite the expected limitations of a leading order strong coupling approximation, the pattern of spins, parities and mass inequalities bear a striking resemblance to the known $QC{D}_4$ glueball spectrum as determined by lattice simulations at weak coupling.