Fronts in dissipative Fermi-Pasta-Ulam-Tsingou chains
Michael Herrmann, Guillaume James, Karsten Matthies
TL;DR
The paper rigorously establishes the existence of traveling front solutions in a dissipative FPUT chain that interpolate between two distinct uniform precompression states in the large‑damping regime. It develops a robust continuum‑limit starting point and uses an implicit function theorem in exponentially weighted Sobolev spaces to construct fronts, while a detailed Fourier‑symbol analysis yields sharp exponential tail rates and monotonicity. The work extends to Hertzian‑type potentials and provides a precise operator‑theoretic framework for the nonlocal fixed‑point problem, including auxiliary ODE representations for tail decay. The results bridge discrete lattice dynamics and continuum descriptions, offering rigorous insight into compression/soliton fronts in damped granular chains and related nonlinear lattices. Overall, the methods yield both existence and quantitative decay information useful for understanding dissipative front propagation in strongly damped, anharmonic chains.
Abstract
In a dissipative Fermi-Pasta-Ulam-Tsingou chain particles interact with their nearest neighbors through anharmonic potentials and linear dissipative forces. We prove the existence of front solutions connecting two different uniformly compressed (or stretched) states at $\pm \infty$ using an implicit function argument starting at a suitable continuum limit in the case of large damping. A detailed analysis allows us to show monotonicity of waves and to determine sharp exponential decay rates for a wide class of potentials including Hertzian potentials.
