From Large N Nonplanar Anomalous Dimensions to Open Spring Theory
  In this note we compute the non-planar one loop anomalous dimension of restricted Schur polynomials that have a bare dimension of O(N). This is achieved by mapping the restricted Schur polynomials into states of a specific U(N) irreducible representation. In this way the dilatation operator is mapped into a u(n) valued operator and, as a result, can easily be diagonalized. The resulting spectrum is reproduced by a classical model of springs between masses. 
Robert de Mello Koch, Garreth Kemp and Stephanie Smith
hep-th