2 problems

Let the paperfolding Hamiltonian be the Hamiltonian generated by the paperfolding substitution sequence, with coupling parameter $\lambda$. Paperfolding spectral conjecture. The pa…

Let a substitution act on either the alphabet $\{0,1\}$ or the alphabet $\{-1,1\}$, and suppose its fixed point is a sequence over that alphabet. A sequence is apwenian if its Hank…