Stable degeneracies for Ising models (Q329948)

The author considers the degeneracies of translation-invariant Ising spin models in which he allows for two-body interactions between all pairs of spins (one discard neighbouring interactions). He is particularly interested in stable degeneracies which cannot be lifted by changing the translation-invariant interactions. The author derives some results on the lower bounds of degeneracy and on the deviation of degeneracy. For instance, he uses substitution techniques to generate spin chain configurations with large stable degeneracy.