An inverse scattering transform for the lattice potential KdV equation. (English) Zbl 1204.35144
Summary: The lattice potential Korteweg-de Vries equation (LKdV) is a partial difference equation in two independent variables, which possesses many properties that are analogous to those of the celebrated Korteweg-de Vries equation. These include discrete soliton solutions, Bäcklund transformations and an associated linear problem, called a Lax pair, for which it provides the compatibility condition. In this paper, we solve the initial value problem for the LKdV equation through a discrete implementation of the inverse scattering transform method applied to the Lax pair. The initial value used for the LKdV equation is assumed to be real and decaying to zero as the absolute value of the discrete spatial variable approaches large values. An interesting feature of our approach is the solution of a discrete Gel’fand-Levitan equation. Moreover, we provide a complete characterization of reflectionless potentials and show that this leads to the Cauchy matrix form of \(N\)-soliton solutions.
MSC:
35Q53 | KdV equations (Korteweg-de Vries equations) |
35R30 | Inverse problems for PDEs |
35A22 | Transform methods (e.g., integral transforms) applied to PDEs |
39A12 | Discrete version of topics in analysis |
37K35 | Lie-Bäcklund and other transformations for infinite-dimensional Hamiltonian and Lagrangian systems |