TY - JOUR T1 - Finite Genus Solutions to a Hierarchy of Integrable Semi-Discrete Equations AU - Xu , Yaru AU - Jia , Minxin AU - Geng , Xianguo AU - Zhai , Yunyun JO - East Asian Journal on Applied Mathematics VL - 1 SP - 80 EP - 112 PY - 2025 DA - 2025/01 SN - 15 DO - http://doi.org/10.4208/eajam.2023-195.251023 UR - https://global-sci.org/intro/article_detail/eajam/23742.html KW - Integrable semi-discrete nonlinear evolution equation, trigonal curve, Baker-Akhiezer function, finite genus solution. AB -

Resorting to the discrete zero-curvature equation and the Lenard recursion equations, a hierarchy of integrable semi-discrete nonlinear evolution equations is derived from a $3 \times 3$ matrix spectral problem with three potentials. Based on the characteristic polynomial of the Lax matrix for the hierarchy, a trigonal curve is introduced, and the properties of the corresponding three-sheeted Riemann surface are studied, including the genus, three kinds of Abelian differentials, Riemann theta functions. The asymptotic properties of the Baker-Akhiezer function and fundamental meromorphic functions defined on the trigonal curve are analyzed with the established theory of trigonal curves. As a result, finite genus solutions of the whole integrable semi-discrete nonlinear evolution hierarchy are obtained.