{"title":"Existence results for some nonlinear elliptic systems on graphs","authors":"Shoudong Man","doi":"10.1016/j.jmaa.2024.128973","DOIUrl":"10.1016/j.jmaa.2024.128973","url":null,"abstract":"<div><div>In this paper, several nonlinear elliptic systems are investigated on graphs. One type of the Sobolev embedding theorem and a new version of the strong maximum principle are established. Then, by using the variational method, the existence of different types of solutions to some elliptic systems is confirmed. Such problems extend the existence results on closed Riemann surface to graphs and extend the existence results for one single equation on graphs by Grigor'yan et al. (2016) <span><span>[12]</span></span> to nonlinear elliptic systems on graphs. Such problems can also be viewed as one type of discrete version of the elliptic systems on Euclidean space and Riemannian manifold.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 2","pages":"Article 128973"},"PeriodicalIF":1.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Remark on square roots of self-adjoint weighted composition operators on H2","authors":"Sungeun Jung , Yoenha Kim , Eungil Ko","doi":"10.1016/j.jmaa.2024.128970","DOIUrl":"10.1016/j.jmaa.2024.128970","url":null,"abstract":"<div><div>In this paper, we study square roots of self-adjoint weighted composition operators on <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>. More precisely, we focus on square roots <span><math><msub><mrow><mi>W</mi></mrow><mrow><mi>f</mi><mo>,</mo><mi>φ</mi></mrow></msub></math></span> of a self-adjoint operator <span><math><msub><mrow><mi>W</mi></mrow><mrow><mi>g</mi><mo>,</mo><mi>ψ</mi></mrow></msub><mo>=</mo><msubsup><mrow><mi>W</mi></mrow><mrow><mi>f</mi><mo>,</mo><mi>φ</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> when <em>φ</em> is a linear fractional selfmap of <span><math><mi>D</mi></math></span>. We also investigate several properties of such <span><math><msub><mrow><mi>W</mi></mrow><mrow><mi>f</mi><mo>,</mo><mi>φ</mi></mrow></msub></math></span>. Finally, we show that the square roots <span><math><msub><mrow><mi>W</mi></mrow><mrow><mi>f</mi><mo>,</mo><mi>φ</mi></mrow></msub></math></span> may be other, nonself-adjoint weighted composition operators and have nontrivial invariant subspaces.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 2","pages":"Article 128970"},"PeriodicalIF":1.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Relative weak compactness in infinite-dimensional Fefferman-Meyer duality","authors":"Vasily Melnikov","doi":"10.1016/j.jmaa.2024.128969","DOIUrl":"10.1016/j.jmaa.2024.128969","url":null,"abstract":"<div><div>Let <em>E</em> be a Banach space such that <span><math><msup><mrow><mi>E</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span> has the Radon-Nikodým property. The aim of this work is to connect relative weak compactness in the <em>E</em>-valued martingale Hardy space <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>(</mo><mi>μ</mi><mo>,</mo><mi>E</mi><mo>)</mo></math></span> to a convex compactness criterion in a weaker topology, such as the topology of uniform convergence on compacts in measure. These results represent a dynamic version of the deep result of Diestel, Ruess, and Schachermayer on relative weak compactness in <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>(</mo><mi>μ</mi><mo>,</mo><mi>E</mi><mo>)</mo></math></span>. In the reflexive case, we obtain a Kadec-Pełczyński dichotomy for <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>(</mo><mi>μ</mi><mo>,</mo><mi>E</mi><mo>)</mo></math></span>-bounded sequences, which decomposes a subsequence into a relatively weakly compact part, a pointwise weakly convexly convergent part, and a null part converging to zero uniformly on compacts in measure. As a corollary, we investigate a parameterized version of the vector-valued Komlós theorem without the assumption of <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>(</mo><mi>μ</mi><mo>,</mo><mi>E</mi><mo>)</mo></math></span>-boundedness.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 1","pages":"Article 128969"},"PeriodicalIF":1.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On p-height orthogonality and characterization of inner product spaces","authors":"Somaye Heidarirad, Ruhollah Jahanipur, Mahdi Dehghani","doi":"10.1016/j.jmaa.2024.128964","DOIUrl":"10.1016/j.jmaa.2024.128964","url":null,"abstract":"<div><div>In this paper, we introduce and study the concept of <em>p</em>-height orthogonality in real normed linear spaces. This orthogonality generalizes the well-known Singer and height orthogonalities. First, we investigate main properties of this type of orthogonality. Then, variety of examples are presented to illustrate the relationship between <em>p</em>-height orthogonality and other previously defined (e.g., isosceles, Singer, height and Birkhoff-James) orthogonalities. Also we investigate the existence properties of this new notion of orthogonality. In particular, <em>α</em>-existence property is established and some interesting bounds for the values of <em>α</em> are obtained. Moreover, some characterizations of inner product spaces are given in terms of <em>p</em>-height orthogonality and its relation with Pythagorean and Birkhoff-James orthogonalities.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 2","pages":"Article 128964"},"PeriodicalIF":1.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chaos of the initial and boundary value problems for the reaction-diffusion equations","authors":"Pengxian Zhu, Qigui Yang","doi":"10.1016/j.jmaa.2024.128946","DOIUrl":"10.1016/j.jmaa.2024.128946","url":null,"abstract":"<div><div>This paper investigates an initial and boundary value problem for the reaction-diffusion equations, which can be considered as a linearized form of the advective Fisher-KPP equations. It is demonstrated that the initial and boundary value problem is chaotic when the three parameters of the reaction-diffusion equation vary above a specific surface. However, stable solutions are obtained both on and below this surface within a particular subset of initial values. The chaos and stability of the nonhomogeneous initial boundary value problem are further studied. Finally, some numerical examples are provided to illustrate the validity of the obtained results.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 2","pages":"Article 128946"},"PeriodicalIF":1.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A porous medium equation with spatially inhomogeneous absorption. Part I: Self-similar solutions","authors":"Razvan Gabriel Iagar , Diana-Rodica Munteanu","doi":"10.1016/j.jmaa.2024.128965","DOIUrl":"10.1016/j.jmaa.2024.128965","url":null,"abstract":"<div><div>This is the first of a two-parts work on the qualitative properties and large time behavior for the following quasilinear equation involving a spatially inhomogeneous absorption<span><span><span><math><msub><mrow><mo>∂</mo></mrow><mrow><mi>t</mi></mrow></msub><mi>u</mi><mo>=</mo><mi>Δ</mi><msup><mrow><mi>u</mi></mrow><mrow><mi>m</mi></mrow></msup><mo>−</mo><mo>|</mo><mi>x</mi><msup><mrow><mo>|</mo></mrow><mrow><mi>σ</mi></mrow></msup><msup><mrow><mi>u</mi></mrow><mrow><mi>p</mi></mrow></msup><mo>,</mo></math></span></span></span> posed for <span><math><mo>(</mo><mi>x</mi><mo>,</mo><mi>t</mi><mo>)</mo><mo>∈</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>N</mi></mrow></msup><mo>×</mo><mo>(</mo><mn>0</mn><mo>,</mo><mo>∞</mo><mo>)</mo></math></span>, <span><math><mi>N</mi><mo>≥</mo><mn>1</mn></math></span>, and in the range of exponents <span><math><mn>1</mn><mo><</mo><mi>m</mi><mo><</mo><mi>p</mi><mo><</mo><mo>∞</mo></math></span>, <span><math><mi>σ</mi><mo>></mo><mn>0</mn></math></span>. We give a complete classification of (singular) self-similar solutions of the form<span><span><span><math><mi>u</mi><mo>(</mo><mi>x</mi><mo>,</mo><mi>t</mi><mo>)</mo><mo>=</mo><msup><mrow><mi>t</mi></mrow><mrow><mo>−</mo><mi>α</mi></mrow></msup><mi>f</mi><mo>(</mo><mo>|</mo><mi>x</mi><mo>|</mo><msup><mrow><mi>t</mi></mrow><mrow><mo>−</mo><mi>β</mi></mrow></msup><mo>)</mo><mo>,</mo><mspace></mspace><mi>α</mi><mo>=</mo><mfrac><mrow><mi>σ</mi><mo>+</mo><mn>2</mn></mrow><mrow><mi>σ</mi><mo>(</mo><mi>m</mi><mo>−</mo><mn>1</mn><mo>)</mo><mo>+</mo><mn>2</mn><mo>(</mo><mi>p</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></mfrac><mo>,</mo><mspace></mspace><mi>β</mi><mo>=</mo><mfrac><mrow><mi>p</mi><mo>−</mo><mi>m</mi></mrow><mrow><mi>σ</mi><mo>(</mo><mi>m</mi><mo>−</mo><mn>1</mn><mo>)</mo><mo>+</mo><mn>2</mn><mo>(</mo><mi>p</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></mfrac><mo>,</mo></math></span></span></span> showing that their form and behavior strongly depends on the critical exponent<span><span><span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>F</mi></mrow></msub><mo>(</mo><mi>σ</mi><mo>)</mo><mo>=</mo><mi>m</mi><mo>+</mo><mfrac><mrow><mi>σ</mi><mo>+</mo><mn>2</mn></mrow><mrow><mi>N</mi></mrow></mfrac><mo>.</mo></math></span></span></span> For <span><math><mi>p</mi><mo>≥</mo><msub><mrow><mi>p</mi></mrow><mrow><mi>F</mi></mrow></msub><mo>(</mo><mi>σ</mi><mo>)</mo></math></span>, we prove that all self-similar solutions have a tail as <span><math><mo>|</mo><mi>x</mi><mo>|</mo><mo>→</mo><mo>∞</mo></math></span> of one of the forms<span><span><span><math><mi>u</mi><mo>(</mo><mi>x</mi><mo>,</mo><mi>t</mi><mo>)</mo><mo>∼</mo><mi>C</mi><mo>|</mo><mi>x</mi><msup><mrow><mo>|</mo></mrow><mrow><mo>−</mo><mo>(</mo><mi>σ</mi><mo>+</mo><mn>2</mn><mo>)</mo><mo>/</mo><mo>(</mo><mi>p</mi><mo>−</mo><mi>m</mi><mo>)</mo></mrow></msup><mspace></mspace><mrow><mi>or</mi></mrow><mspace></mspace><mi>u</mi><mo>(</mo><mi>x</mi><mo>,</mo><mi>t</mi><mo>)</mo><mo>∼</mo><msup><mrow><mo>(","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 1","pages":"Article 128965"},"PeriodicalIF":1.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Jacobi spectral methods for system of nonlinear Volterra Urysohn integral equations","authors":"Samiran Chakraborty , Gnaneshwar Nelakanti","doi":"10.1016/j.jmaa.2024.128956","DOIUrl":"10.1016/j.jmaa.2024.128956","url":null,"abstract":"<div><div>In this article, Galerkin, multi-Galerkin methods and their iterated versions based on Jacobi polynomials are exerted to approximate and obtain superconvergence rates for the system of nonlinear Volterra integral equations of the Urysohn type with both smooth and weakly singular kernels. Firstly, we establish the regularity behaviors of the solutions of the system of the nonlinear second kind Volterra integral equations. We determine convergence results for Jacobi spectral Galerkin method and its iterated version in both weighted-<span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> as well as infinity norms and show that the iterated version provides better approximation. Furthermore, we improve the superconvergence rates for both the smooth as well as the weakly singular kernels in Jacobi spectral iterated multi-Galerkin method. The reliability and efficiency of the theoretical results are verified with numerical experiments.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 1","pages":"Article 128956"},"PeriodicalIF":1.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Understanding of linear operators through Wigner analysis","authors":"Elena Cordero , Gianluca Giacchi , Edoardo Pucci","doi":"10.1016/j.jmaa.2024.128955","DOIUrl":"10.1016/j.jmaa.2024.128955","url":null,"abstract":"<div><div>In this work, we extend Wigner's original framework to analyze linear operators by examining the relationship between their Wigner and Schwartz kernels. Our approach includes the introduction of (quasi-)algebras of Fourier integral operators (FIOs), which encompass FIOs of type I and II. The symbols of these operators belong to (weighted) modulation spaces, particularly in Sjöstrand's class, known for its favorable properties in time-frequency analysis. One of the significant results of our study is demonstrating the inverse-closedness of these symbol classes.</div><div>Our analysis includes fundamental examples such as pseudodifferential operators and Fourier integral operators related to Schrödinger-type equations. These examples typically feature classical Hamiltonian flows governed by linear symplectic transformations <span><math><mi>S</mi><mo>∈</mo><mi>S</mi><mi>p</mi><mo>(</mo><mi>d</mi><mo>,</mo><mi>R</mi><mo>)</mo></math></span>. The core idea of our approach is to utilize the Wigner kernel to transform a Fourier integral operator <em>T</em> on <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span> into a pseudodifferential operator <em>K</em> on <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn><mi>d</mi></mrow></msup></math></span>. This transformation involves a symbol <em>σ</em> well-localized around the manifold defined by <span><math><mi>z</mi><mo>=</mo><mi>S</mi><mi>w</mi></math></span>.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 1","pages":"Article 128955"},"PeriodicalIF":1.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the total number of ones associated with cranks of partitions modulo 11","authors":"Dandan Chen , Rong Chen , Siyu Yin","doi":"10.1016/j.jmaa.2024.128954","DOIUrl":"10.1016/j.jmaa.2024.128954","url":null,"abstract":"<div><div>In 2021, Andrews mentioned that George Beck introduced partition statistics <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><mi>r</mi><mo>,</mo><mi>m</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span>, which denote the total number of ones in the partition of <em>n</em> with crank congruent to <em>r</em> modulo <em>m</em>. Recently, a number of congruences and identities involving <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><mi>r</mi><mo>,</mo><mi>m</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span> for some small <em>m</em> have been developed. We establish the 11-dissection of the generating functions for <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>ω</mi></mrow></msub><mo>(</mo><mi>r</mi><mo>,</mo><mn>11</mn><mo>,</mo><mi>n</mi><mo>)</mo><mo>−</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>ω</mi></mrow></msub><mo>(</mo><mn>11</mn><mo>−</mo><mi>r</mi><mo>,</mo><mn>11</mn><mo>,</mo><mi>n</mi><mo>)</mo></math></span>, where <span><math><mi>r</mi><mo>=</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>3</mn><mo>,</mo><mn>4</mn><mo>,</mo><mn>5</mn></math></span>. In particular, we discover a beautiful identity involving <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>ω</mi></mrow></msub><mo>(</mo><mi>r</mi><mo>,</mo><mn>11</mn><mo>,</mo><mn>11</mn><mi>n</mi><mo>+</mo><mn>6</mn><mo>)</mo></math></span>.</div></div>","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 1","pages":"Article 128954"},"PeriodicalIF":1.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the completeness property of root vector systems for 2 × 2 Dirac type operators with non-regular boundary conditions","authors":"Anton A. Lunyov , Mark M. Malamud","doi":"10.1016/j.jmaa.2024.128949","DOIUrl":"10.1016/j.jmaa.2024.128949","url":null,"abstract":"<div><div>The paper is concerned with the completeness property of a system of root vectors of a boundary value problem for the following <span><math><mn>2</mn><mo>×</mo><mn>2</mn></math></span> Dirac type equation<span><span><span><math><mi>L</mi><mi>y</mi><mo>=</mo><mo>−</mo><mi>i</mi><msup><mrow><mi>B</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><msup><mrow><mi>y</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>+</mo><mi>Q</mi><mo>(</mo><mi>x</mi><mo>)</mo><mi>y</mi><mo>=</mo><mi>λ</mi><mi>y</mi><mo>,</mo><mspace></mspace><mi>y</mi><mo>=</mo><mi>col</mi><mo>(</mo><msub><mrow><mi>y</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>y</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo><mo>,</mo><mspace></mspace><mi>x</mi><mo>∈</mo><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo><mo>,</mo><mi>B</mi><mo>=</mo><mi>diag</mi><mo>(</mo><msub><mrow><mi>b</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>b</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo><mo>,</mo><mspace></mspace><msub><mrow><mi>b</mi></mrow><mrow><mn>1</mn></mrow></msub><mo><</mo><mn>0</mn><mo><</mo><msub><mrow><mi>b</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>,</mo><mspace></mspace><mtext>and</mtext><mspace></mspace><mi>Q</mi><mo>∈</mo><msubsup><mrow><mi>W</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>n</mi></mrow></msubsup><mo>[</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>]</mo><mo>⊗</mo><msup><mrow><mi>C</mi></mrow><mrow><mn>2</mn><mo>×</mo><mn>2</mn></mrow></msup><mo>,</mo></math></span></span></span> subject to general non-regular two-point boundary conditions <span><math><mi>C</mi><mi>y</mi><mo>(</mo><mn>0</mn><mo>)</mo><mo>+</mo><mi>D</mi><mi>y</mi><mo>(</mo><mn>1</mn><mo>)</mo><mo>=</mo><mn>0</mn></math></span>. If <span><math><msub><mrow><mi>b</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mo>−</mo><msub><mrow><mi>b</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>1</mn></math></span>, this equation is equivalent to the one dimensional Dirac equation.</div><div>We establish a new completeness result for the system of root vectors of such boundary value problem with <em>non-regular and even degenerate</em> boundary conditions. We also present several explicit completeness results in terms of values <span><math><msup><mrow><mi>Q</mi></mrow><mrow><mo>(</mo><mi>j</mi><mo>)</mo></mrow></msup><mo>(</mo><mn>0</mn><mo>)</mo></math></span> and <span><math><msup><mrow><mi>Q</mi></mrow><mrow><mo>(</mo><mi>j</mi><mo>)</mo></mrow></msup><mo>(</mo><mn>1</mn><mo>)</mo></math></span>. In the case of degenerate boundary conditions and the analytic <span><math><mi>Q</mi><mo>(</mo><mo>⋅</mo><mo>)</mo></math></span>, the criterion of the completeness property is established. We demonstrate our results on the explicit example of a complete system of vector quasi-exponential polynomials.</div><div>Applications to the spectral synthesis for Dirac type operators are discussed. Moreover, applications to the completeness property for the damped string e","PeriodicalId":50147,"journal":{"name":"Journal of Mathematical Analysis and Applications","volume":"543 2","pages":"Article 128949"},"PeriodicalIF":1.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}