{"title":"单时滞线性矩阵离散方程解的表示","authors":"Josef Diblík","doi":"10.1016/j.aml.2025.109577","DOIUrl":null,"url":null,"abstract":"<div><div>A linear matrix delayed discrete equation <span><span><span><math><mrow><mi>Δ</mi><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>=</mo><mi>B</mi><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>−</mo><mi>m</mi><mo>)</mo></mrow><mo>+</mo><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>−</mo><mi>m</mi><mo>)</mo></mrow><mi>C</mi><mo>+</mo><mi>F</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>,</mo></mrow></math></span></span></span>is considered, where <span><math><mi>m</mi></math></span> is a fixed positive integer, <span><math><mrow><mi>k</mi><mo>=</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>,</mo><mo>…</mo><mspace></mspace></mrow></math></span> is a discrete independent variable, <span><math><mrow><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math></span> is an <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> unknown variable matrix, <span><math><mi>Δ</mi></math></span> is the first order forward difference, <span><math><mi>B</mi></math></span>, <span><math><mi>C</mi></math></span> are given <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> constant matrices, and <span><math><mrow><mi>F</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math></span> is a given <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> variable matrix. Using a special matrix function, under some commutativity conditions, formulas are derived, solving an initial problem <span><math><mrow><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>=</mo><mi>Ψ</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math></span>, <span><math><mrow><mi>k</mi><mo>=</mo><mo>−</mo><mi>m</mi><mo>,</mo><mo>−</mo><mi>m</mi><mo>+</mo><mn>1</mn><mo>,</mo><mo>…</mo><mo>,</mo><mn>0</mn></mrow></math></span>, where <span><math><mrow><mi>Ψ</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math></span> is an <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> variable matrix. Some connections with previously known results are discussed with open problems suggested for further investigations.</div></div>","PeriodicalId":55497,"journal":{"name":"Applied Mathematics Letters","volume":"168 ","pages":"Article 109577"},"PeriodicalIF":2.9000,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Representation of solutions to a linear matrix discrete equation with single delay\",\"authors\":\"Josef Diblík\",\"doi\":\"10.1016/j.aml.2025.109577\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>A linear matrix delayed discrete equation <span><span><span><math><mrow><mi>Δ</mi><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>=</mo><mi>B</mi><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>−</mo><mi>m</mi><mo>)</mo></mrow><mo>+</mo><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>−</mo><mi>m</mi><mo>)</mo></mrow><mi>C</mi><mo>+</mo><mi>F</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>,</mo></mrow></math></span></span></span>is considered, where <span><math><mi>m</mi></math></span> is a fixed positive integer, <span><math><mrow><mi>k</mi><mo>=</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>,</mo><mo>…</mo><mspace></mspace></mrow></math></span> is a discrete independent variable, <span><math><mrow><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math></span> is an <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> unknown variable matrix, <span><math><mi>Δ</mi></math></span> is the first order forward difference, <span><math><mi>B</mi></math></span>, <span><math><mi>C</mi></math></span> are given <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> constant matrices, and <span><math><mrow><mi>F</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math></span> is a given <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> variable matrix. Using a special matrix function, under some commutativity conditions, formulas are derived, solving an initial problem <span><math><mrow><mi>X</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>=</mo><mi>Ψ</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math></span>, <span><math><mrow><mi>k</mi><mo>=</mo><mo>−</mo><mi>m</mi><mo>,</mo><mo>−</mo><mi>m</mi><mo>+</mo><mn>1</mn><mo>,</mo><mo>…</mo><mo>,</mo><mn>0</mn></mrow></math></span>, where <span><math><mrow><mi>Ψ</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math></span> is an <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> variable matrix. Some connections with previously known results are discussed with open problems suggested for further investigations.</div></div>\",\"PeriodicalId\":55497,\"journal\":{\"name\":\"Applied Mathematics Letters\",\"volume\":\"168 \",\"pages\":\"Article 109577\"},\"PeriodicalIF\":2.9000,\"publicationDate\":\"2025-04-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Mathematics Letters\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0893965925001272\",\"RegionNum\":2,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Mathematics Letters","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0893965925001272","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
摘要
考虑一个线性矩阵延迟离散方程ΔX(k)=BX(k−m)+X(k−m)C+F(k),其中m为固定正整数,k=0,1,…为离散自变量,X(k)为n×n未知变量矩阵,Δ为一阶正差分,B, C为给定n×n常数矩阵,F(k)为给定n×n变量矩阵。利用一个特殊的矩阵函数,在某些交换性条件下,导出了求解初始问题X(k)=Ψ(k), k= - m, - m+1,…,0的公式,其中Ψ(k)是一个n×n变量矩阵。讨论了与先前已知结果的一些联系,并提出了有待进一步研究的开放性问题。
Representation of solutions to a linear matrix discrete equation with single delay
A linear matrix delayed discrete equation is considered, where is a fixed positive integer, is a discrete independent variable, is an unknown variable matrix, is the first order forward difference, , are given constant matrices, and is a given variable matrix. Using a special matrix function, under some commutativity conditions, formulas are derived, solving an initial problem , , where is an variable matrix. Some connections with previously known results are discussed with open problems suggested for further investigations.
期刊介绍:
The purpose of Applied Mathematics Letters is to provide a means of rapid publication for important but brief applied mathematical papers. The brief descriptions of any work involving a novel application or utilization of mathematics, or a development in the methodology of applied mathematics is a potential contribution for this journal. This journal''s focus is on applied mathematics topics based on differential equations and linear algebra. Priority will be given to submissions that are likely to appeal to a wide audience.