An improved holographic picture of the pion

The holographic light-front Schrödinger Equation, which governs transverse dynamics in mesons, predicts a massless pion. To generate the pion’s physical mass, one must incorporate longitudinal dynamics. Two ways for doing so are via the (1 + 1)-dimensional ’t Hooft and Li-Vary equations. Despite having distinct potential operators, these two equations are degenerate in their description of pion observables. We explore this degeneracy using an ansatz that accommodates the ’t Hooft and Li-Vary equations as well as a string equation in (2 + 1)-dimensional anti de Sitter spacetime, recently derived by Vegh. We highlight a scenario where the degeneracy extends beyond the ’t Hooft and Li-Vary limits to the weak coupling limit of the string equation. This talk is based on [1].