Baryons and branes in anti de Sitter space

In the mapping from four-dimensional gauge theories to string theory in AdS space, many features of gauge theory can be described by branes wrapped in different ways on S⁵, RP⁵, or subspaces therefore. These include a baryon vertex coupling N external charges in the fundamental representation of SU(N), a bound state of k gluons in SO(2k) gauge theory, strings coupled to external charges in the spinor representation of the gauge group, and domain walls across which the low energy gauge group changes.