{"title":"Optimal bisections of directed graphs","authors":"Guanwu Liu, Jie Ma, C. Zu","doi":"10.1002/rsa.21175","DOIUrl":null,"url":null,"abstract":"In this article, motivated by a problem of Scott [Surveys in combinatorics, 327 (2005), 95‐117.] and a conjecture of Lee et al. [Random Struct. Algorithm, 48 (2016), 147‐170.] we consider bisections of directed graphs. We prove that every directed graph with arcs and minimum semidegree at least admits a bisection in which at least arcs cross in each direction. This provides an optimal bound as well as a positive answer to a question of Hou and Wu [J. Comb. Theory B, 132 (2018), 107‐133.] in a stronger form.","PeriodicalId":54523,"journal":{"name":"Random Structures & Algorithms","volume":"26 1","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Random Structures & Algorithms","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1002/rsa.21175","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"COMPUTER SCIENCE, SOFTWARE ENGINEERING","Score":null,"Total":0}
引用次数: 0
Abstract
In this article, motivated by a problem of Scott [Surveys in combinatorics, 327 (2005), 95‐117.] and a conjecture of Lee et al. [Random Struct. Algorithm, 48 (2016), 147‐170.] we consider bisections of directed graphs. We prove that every directed graph with arcs and minimum semidegree at least admits a bisection in which at least arcs cross in each direction. This provides an optimal bound as well as a positive answer to a question of Hou and Wu [J. Comb. Theory B, 132 (2018), 107‐133.] in a stronger form.
期刊介绍:
It is the aim of this journal to meet two main objectives: to cover the latest research on discrete random structures, and to present applications of such research to problems in combinatorics and computer science. The goal is to provide a natural home for a significant body of current research, and a useful forum for ideas on future studies in randomness.
Results concerning random graphs, hypergraphs, matroids, trees, mappings, permutations, matrices, sets and orders, as well as stochastic graph processes and networks are presented with particular emphasis on the use of probabilistic methods in combinatorics as developed by Paul Erdõs. The journal focuses on probabilistic algorithms, average case analysis of deterministic algorithms, and applications of probabilistic methods to cryptography, data structures, searching and sorting. The journal also devotes space to such areas of probability theory as percolation, random walks and combinatorial aspects of probability.