I will talk about the spectrum of open strings states stretching between
giant gravitons and how their energies are obtained from perturbative
computations in N=4 SYM and some of its deformations. I will show that the
energy of these states is controlled by central charge extension of the
infinite spin chain and how the finite boundary conditions source
non-trivial valuers for the central charge. I will further argue how this
central charge in a particular limit can be identified with the central
charge extension of the Coulomb branch of N=4 SYM.