Exact Diatomic Fermi--Pasta--Ulam--Tsingou Solitary Waves with Optical Band Ripples at Infinity
Exact Diatomic Fermi--Pasta--Ulam--Tsingou Solitary Waves with Optical Band Ripples at Infinity
We study the existence of solitary waves in a diatomic Fermi--Pasta--Ulam--Tsingou (FPUT) lattice. For monatomic FPUT the traveling wave equations are a regular perturbation of the Korteweg--de Vries (KdV) equations but, surprisingly, we find that for the diatomic lattice the traveling wave equations are a singular perturbation of KdV's. Using …