Toy models for wrapping effects

Understand

The anomalous dimensions of local single trace gauge invariant operators in N=4 supersymmetric Yang-Mills theory can be computed by diagonalizing a long range integrable Hamiltonian by means of perturbative asymptotic Bethe ansatz.

• This formalism breaks down when the number of fields of the composite operator is smaller than the range of the Hamiltonian which coincides with the order in perturbation theory at study.
• We analyze two spin chain toy models which might shed some light on the physics behind these wrapping effects.
• One of them, the Hubbard model, is known to be closely related to N=4 SYM.