基于图a α-谱半径大小的因子{K1,2,K1,3,K5}的存在性

IF 1 3区 数学 Q3 MATHEMATICS, APPLIED
Xianglong Zhang, Lihua You
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A <span><math><mrow><mo>{</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>5</mn></mrow></msub><mo>}</mo></mrow></math></span>-factor of <span><math><mi>G</mi></math></span> is a spanning subgraph of <span><math><mi>G</mi></math></span>, in which each component is isomorphic to a member in <span><math><mrow><mo>{</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>5</mn></mrow></msub><mo>}</mo></mrow></math></span>. The <span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span>-spectral radius of <span><math><mi>G</mi></math></span> is denoted by <span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>α</mi></mrow></msub><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow></mrow></math></span>. In this paper, we obtain a lower bound on the size (resp. the <span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span>-spectral radius for <span><math><mrow><mi>α</mi><mo>∈</mo><mrow><mo>[</mo><mn>0</mn><mo>,</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>]</mo></mrow></mrow></math></span>) of <span><math><mi>G</mi></math></span> to guarantee that <span><math><mi>G</mi></math></span> has a <span><math><mrow><mo>{</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>5</mn></mrow></msub><mo>}</mo></mrow></math></span>-factor, and show that <span><math><mi>G</mi></math></span> has a <span><math><mrow><mo>{</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>5</mn></mrow></msub><mo>}</mo></mrow></math></span>-factor if <span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>α</mi></mrow></msub><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mo>&gt;</mo><mi>τ</mi><mrow><mo>(</mo><mi>n</mi><mo>)</mo></mrow></mrow></math></span>, where <span><math><mrow><mi>τ</mi><mrow><mo>(</mo><mi>n</mi><mo>)</mo></mrow></mrow></math></span> is the largest root of <span><math><mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>−</mo><mrow><mo>(</mo><mrow><mo>(</mo><mi>α</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow><mi>n</mi><mo>+</mo><mi>α</mi><mo>−</mo><mn>3</mn><mo>)</mo></mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mrow><mo>(</mo><mi>α</mi><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mrow><mo>(</mo><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mi>α</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow><mi>n</mi><mo>−</mo><mn>2</mn><mi>α</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow><mi>x</mi><mo>−</mo><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mrow><mo>(</mo><mn>3</mn><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mi>α</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow><mi>n</mi><mo>−</mo><mn>4</mn><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mn>5</mn><mi>α</mi><mo>−</mo><mn>3</mn><mo>=</mo><mn>0</mn></mrow></math></span>.</div></div>","PeriodicalId":50573,"journal":{"name":"Discrete Applied Mathematics","volume":"376 ","pages":"Pages 22-30"},"PeriodicalIF":1.0000,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The existence of a {K1,2,K1,3,K5}-factor based on the size or the Aα-spectral radius of graphs\",\"authors\":\"Xianglong Zhang,&nbsp;Lihua You\",\"doi\":\"10.1016/j.dam.2025.06.003\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Let <span><math><mi>G</mi></math></span> be a connected graph of order <span><math><mi>n</mi></math></span>. A <span><math><mrow><mo>{</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>5</mn></mrow></msub><mo>}</mo></mrow></math></span>-factor of <span><math><mi>G</mi></math></span> is a spanning subgraph of <span><math><mi>G</mi></math></span>, in which each component is isomorphic to a member in <span><math><mrow><mo>{</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>5</mn></mrow></msub><mo>}</mo></mrow></math></span>. The <span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span>-spectral radius of <span><math><mi>G</mi></math></span> is denoted by <span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>α</mi></mrow></msub><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow></mrow></math></span>. In this paper, we obtain a lower bound on the size (resp. the <span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span>-spectral radius for <span><math><mrow><mi>α</mi><mo>∈</mo><mrow><mo>[</mo><mn>0</mn><mo>,</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mo>]</mo></mrow></mrow></math></span>) of <span><math><mi>G</mi></math></span> to guarantee that <span><math><mi>G</mi></math></span> has a <span><math><mrow><mo>{</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>5</mn></mrow></msub><mo>}</mo></mrow></math></span>-factor, and show that <span><math><mi>G</mi></math></span> has a <span><math><mrow><mo>{</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn></mrow></msub><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mn>5</mn></mrow></msub><mo>}</mo></mrow></math></span>-factor if <span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>α</mi></mrow></msub><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mo>&gt;</mo><mi>τ</mi><mrow><mo>(</mo><mi>n</mi><mo>)</mo></mrow></mrow></math></span>, where <span><math><mrow><mi>τ</mi><mrow><mo>(</mo><mi>n</mi><mo>)</mo></mrow></mrow></math></span> is the largest root of <span><math><mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>−</mo><mrow><mo>(</mo><mrow><mo>(</mo><mi>α</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow><mi>n</mi><mo>+</mo><mi>α</mi><mo>−</mo><mn>3</mn><mo>)</mo></mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mrow><mo>(</mo><mi>α</mi><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mrow><mo>(</mo><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mi>α</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow><mi>n</mi><mo>−</mo><mn>2</mn><mi>α</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow><mi>x</mi><mo>−</mo><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mrow><mo>(</mo><mn>3</mn><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mi>α</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow><mi>n</mi><mo>−</mo><mn>4</mn><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mn>5</mn><mi>α</mi><mo>−</mo><mn>3</mn><mo>=</mo><mn>0</mn></mrow></math></span>.</div></div>\",\"PeriodicalId\":50573,\"journal\":{\"name\":\"Discrete Applied Mathematics\",\"volume\":\"376 \",\"pages\":\"Pages 22-30\"},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2025-06-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Discrete Applied Mathematics\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0166218X2500318X\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Discrete Applied Mathematics","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0166218X2500318X","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
引用次数: 0

摘要

设G是一个n阶连通图,a {K1,2,K1,3,K5}是G的一个生成子图,其中每个分量同构于{K1,2,K1,3,K5}中的一个元素。G的a α-谱半径用ρα(G)表示。在本文中,我们得到了一个大小的下界。求出G的α∈[0,12])的a α-谱半径,以保证G具有{K1,2,K1,3,K5}-因子,并证明当ρα(G)>τ(n)时G具有{K1,2,K1,3,K5}-因子,其中τ(n)是x3−((α+1)n+ (α2 - α−1)n−2α+1)x−α2n2+(3α2 - α+1)n−4α2+5α−3=0的最大根。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
The existence of a {K1,2,K1,3,K5}-factor based on the size or the Aα-spectral radius of graphs
Let G be a connected graph of order n. A {K1,2,K1,3,K5}-factor of G is a spanning subgraph of G, in which each component is isomorphic to a member in {K1,2,K1,3,K5}. The Aα-spectral radius of G is denoted by ρα(G). In this paper, we obtain a lower bound on the size (resp. the Aα-spectral radius for α[0,12]) of G to guarantee that G has a {K1,2,K1,3,K5}-factor, and show that G has a {K1,2,K1,3,K5}-factor if ρα(G)>τ(n), where τ(n) is the largest root of x3((α+1)n+α3)x2+(αn2+(α2α1)n2α+1)xα2n2+(3α2α+1)n4α2+5α3=0.
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来源期刊
Discrete Applied Mathematics
Discrete Applied Mathematics 数学-应用数学
CiteScore
2.30
自引率
9.10%
发文量
422
审稿时长
4.5 months
期刊介绍: The aim of Discrete Applied Mathematics is to bring together research papers in different areas of algorithmic and applicable discrete mathematics as well as applications of combinatorial mathematics to informatics and various areas of science and technology. Contributions presented to the journal can be research papers, short notes, surveys, and possibly research problems. The "Communications" section will be devoted to the fastest possible publication of recent research results that are checked and recommended for publication by a member of the Editorial Board. The journal will also publish a limited number of book announcements as well as proceedings of conferences. These proceedings will be fully refereed and adhere to the normal standards of the journal. Potential authors are advised to view the journal and the open calls-for-papers of special issues before submitting their manuscripts. Only high-quality, original work that is within the scope of the journal or the targeted special issue will be considered.
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