{"title":"N Double-Pole Solutions of the Matrix-Type Nonlinear Schrödinger Equation Under Zero and Nonzero Boundary Conditions","authors":"Guofei Zhang, Jingsong He, Yi Cheng","doi":"10.1111/sapm.70067","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>In this paper, Riemann–Hilbert (RH) method is developed for the initial value problem of matrix-type nonlinear Schrödinger equation with discrete spectrum as double poles under zero and nonzero boundary conditions, respectively, which all include the process of direct scattering(the analyticity, symmetries and asymptotics of the Jost function, scattering, and reflection coefficients) and inverse scattering (residue conditions, norming constants, RH problem, and the reconstruction formula). Since the object of study is a matrix-type system, we will point out the similarities and differences between it and the RH method in the study of scalar and vector equations, such as we have to assume that <span></span><math>\n <semantics>\n <mrow>\n <mi>k</mi>\n <mo>=</mo>\n <msub>\n <mi>k</mi>\n <mi>n</mi>\n </msub>\n <mo>∈</mo>\n <msup>\n <mi>C</mi>\n <mo>+</mo>\n </msup>\n </mrow>\n <annotation>$k=k_{n}\\in \\mathbb {C}^{+}$</annotation>\n </semantics></math> is a third order zero of <span></span><math>\n <semantics>\n <mrow>\n <mo>det</mo>\n <mi>a</mi>\n <mo>(</mo>\n <mi>k</mi>\n <mo>)</mo>\n </mrow>\n <annotation>$\\det a(k)$</annotation>\n </semantics></math> under <span></span><math>\n <semantics>\n <mrow>\n <mi>rank</mi>\n <mrow>\n <mo>(</mo>\n <mi>P</mi>\n <mrow>\n <mo>(</mo>\n <mi>x</mi>\n <mo>,</mo>\n <mi>t</mi>\n <mo>,</mo>\n <msub>\n <mi>k</mi>\n <mi>n</mi>\n </msub>\n <mo>)</mo>\n </mrow>\n <mo>)</mo>\n </mrow>\n <mo>=</mo>\n <mn>2</mn>\n <mfenced>\n <mo>⇔</mo>\n <mi>rank</mi>\n <mo>(</mo>\n <mi>a</mi>\n <mrow>\n <mo>(</mo>\n <msub>\n <mi>k</mi>\n <mi>n</mi>\n </msub>\n <mo>)</mo>\n </mrow>\n <mo>)</mo>\n <mo>=</mo>\n <mn>0</mn>\n </mfenced>\n </mrow>\n <annotation>$\\mathrm{rank} (P(x,t,k_{n}))=2 \\left(\\Leftrightarrow \\mathrm{rank}(a(k_{n}))=0 \\right)$</annotation>\n </semantics></math>, and so on.</p></div>","PeriodicalId":51174,"journal":{"name":"Studies in Applied Mathematics","volume":"154 6","pages":""},"PeriodicalIF":2.3000,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Studies in Applied Mathematics","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/sapm.70067","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper, Riemann–Hilbert (RH) method is developed for the initial value problem of matrix-type nonlinear Schrödinger equation with discrete spectrum as double poles under zero and nonzero boundary conditions, respectively, which all include the process of direct scattering(the analyticity, symmetries and asymptotics of the Jost function, scattering, and reflection coefficients) and inverse scattering (residue conditions, norming constants, RH problem, and the reconstruction formula). Since the object of study is a matrix-type system, we will point out the similarities and differences between it and the RH method in the study of scalar and vector equations, such as we have to assume that is a third order zero of under , and so on.
期刊介绍:
Studies in Applied Mathematics explores the interplay between mathematics and the applied disciplines. It publishes papers that advance the understanding of physical processes, or develop new mathematical techniques applicable to physical and real-world problems. Its main themes include (but are not limited to) nonlinear phenomena, mathematical modeling, integrable systems, asymptotic analysis, inverse problems, numerical analysis, dynamical systems, scientific computing and applications to areas such as fluid mechanics, mathematical biology, and optics.