We compute sigma model solutions for rigidly rotating open strings suspended between giant gravitons in general LLM geometries. These solutions are confined to the LLM plane. These all have a dispersion relation for ∆ − J that is consistent with saturation of a BPS bound of the centrally extended spin chain. For the special case of circularly symmetric LLM geometries, we can further evaluate the amount of angular momentum J carried by these strings. This quantity diverges for string configurations that try to move between different “coloring regions” in the LLM plane. All of these quantities have a perturbative expansion in the t’Hooft coupling. For the strings suspended between AdS giants, we can compute in field theory the leading result of J carried by the string via an analytic continuation of the SU(2) result, with the help of the Bethe Ansatz for the SL(2) sector. We thus provide additional information on how the radial direction of AdS arises from (open) spin chain calculations.

We study classical solutions to the Nambu-Goto string on AdS2× S1 and AdS3× S1 corresponding to strings stretched between wrapped branes extending in AdS. The solutions are obtained by analytic continuation of giant magnon solutions, cut at the position of the branes. These solutions carry one or two SO(2, 4) charges and a single SO(6) charge. We compute their energies and show their relation to $$ \frac{1}{2} $$ 1 2 -BPS geometries. Their relevance to the SL(2) sector of $$ \mathcal{N} $$ N = 4 SYM is also discussed.

We study integrable non-diagonal open boundary conditions for spin chains arising from holographic gauge theories. Their dual description is in terms of open strings stretching between giant gravitons intersecting at arbitrary angles inside spheres or projective spaces. By studying properties of their ground and low-lying states we reproduce the expected spectrum near the intersections. Unlike the case of intersecting D-branes in flat space, intersecting giant gravitons related by SU (N ) rotations do not always preserve an additional supersymmetry. We quantify this lack of enhancement by whether or not there exists a simple ferromagnetic ground state for the open spin chain.

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We construct (p, q) string junction solutions suspended between both sphere and AdS giant gravitons in AdS 5 × S 5 . Our results extend easily to more general half BPS geometries of LLM type. These carry angular momentum in the directions of the worldvolume of the giant gravitons. We argue that these are charged under a central extension of the supersymmetry algebra similar to the one that has appeared in the works of Beisert for the N = 4 spin chain. We also argue that they are BPS with respect to this central extension. We show that apart from some kinematical details, the junctions end up solving the same minimization problem that appears in the Coulomb branch of N = 4 SYM. Their mass and shape is independent of the angular momentum Q that the junction carries.