Hydrodynamics of the Fermi-Pasta-Ulam-Tsingou chain (opens in new tab)

We provide a pedagogical review of the hydrodynamics of the FPUT chain. There are three hydrodynamic fields corresponding to the conservation of mass, momentum and energy. We provide physically motivated derivations of the hydrodynamic equations at the levels of Euler and then Navier-Stokes-Fourier. Next we consider examples to test as to how successful the hydrodynamic description is in predicting the observed time evolution of nonequilibrium i...