The two breathers solution to the nonlinear coupled Klein-Gordon equation is analyzed to show that the breather resonances exist between them. There are two types of singular interactions: One is the resonant interaction where two breathers interact so as to make a new breather, the other is the extremely long-range interaction where two breathers interact infinitely apart from each other. (C) 2000 Elsevier Science B.V.
Arai, T., & Tajiri, M. (2000). Resonance of breathers in one dimension: Solutions to the nonlinear coupled Klein-Gordon equation. Physics Letters, Section A: General, Atomic and Solid State Physics, 274(1–2), 18–26. https://doi.org/10.1016/S0375-9601(00)00521-1