Resonant interactions in the $\alpha$-FPUT lattice with site-dependent coefficients (opens in new tab)

The wave turbulence framework has proven to be an effective tool for analyzing certain features of nonlinear energy transfer in one-dimensional nonlinear chains. In this work, we extend this approach to the $\alpha$-FPUT problem when the spring stiffness $\chi$ and the nonlinear coefficient $\alpha$ are site-dependent. Although three-wave interactions are non-resonant for constant coefficients, their spatial modulation gives rise to a non-trivia...