{"title":"Extremal trees with fixed order and diameter for average size of maximal matchings","authors":"Lukai Sui, Qiuli Li","doi":"10.1016/j.dam.2025.08.016","DOIUrl":null,"url":null,"abstract":"<div><div>This paper characterizes the classes of graphs whose average sizes of maximal matchings achieve the extremum in trees with fixed order and diameter. Regarding the conjecture posed by Engbers and Erey about the minimum case, we confirm it for trees of fixed order with diameters 6, 7 and 8. Furthermore, we also confirm the conjecture for the maximum case in trees of fixed order with diameter 6. Our proofs base on a meticulous analysis of graph structures and a thorough exploration of matching theory. By studying trees with different diameters, we discover some interesting properties and patterns, which provide insights for further research.</div></div>","PeriodicalId":50573,"journal":{"name":"Discrete Applied Mathematics","volume":"377 ","pages":"Pages 518-528"},"PeriodicalIF":1.0000,"publicationDate":"2025-08-20","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/S0166218X25004573","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
Abstract
This paper characterizes the classes of graphs whose average sizes of maximal matchings achieve the extremum in trees with fixed order and diameter. Regarding the conjecture posed by Engbers and Erey about the minimum case, we confirm it for trees of fixed order with diameters 6, 7 and 8. Furthermore, we also confirm the conjecture for the maximum case in trees of fixed order with diameter 6. Our proofs base on a meticulous analysis of graph structures and a thorough exploration of matching theory. By studying trees with different diameters, we discover some interesting properties and patterns, which provide insights for further research.
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.