{"title":"Faudree-Lehel猜想的推广对随机图几乎成立","authors":"J. Przybylo","doi":"10.1002/rsa.21058","DOIUrl":null,"url":null,"abstract":"The irregularity strength of a simple graph G=(V,E) , denoted s(G) is a certain measure of the level of irregularity of a graph. It indicates how hard it is to make an irregular multigraph of G via multiplication of its selected edges. It is however more commonly set forth through k‐weightings, that is, mappings ω:E→{1,2,…,k} , assigning every vertex v∈V the weighted degree σ(v):=∑e∋vω(e) . In this setting, s(G) is precisely defined as the least k admitting a k‐weighting of G which attributes pairwise distinct weighted degrees to all vertices of G. It is known that s(G)>n/d in the case of d‐regular graphs with order n and d>1 . An open conjecture of Faudree and Lehel from the 1980s states that s(G)≤n/d+c in turn for some finite constant c independent of d. It is believed that the natural strengthening of this conjecture toward all graphs where d is substituted by the minimum degree δ should also hold. We confirm this supposition in the case of random graphs. Namely, we show that asymptotically almost surely the generalization of Faudree‐Lehel Conjecture holds for a random graph G∈𝒢(n,p) for any constant p, that is, that s(G) takes one of the three values: ⌈n/δ⌉ , ⌈n/δ⌉+1 , or ⌈n/δ⌉+2 . This is implied by the fact that a.a.s. p−1","PeriodicalId":54523,"journal":{"name":"Random Structures & Algorithms","volume":"5 1","pages":"383 - 396"},"PeriodicalIF":0.9000,"publicationDate":"2021-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"A generalization of Faudree–Lehel conjecture holds almost surely for random graphs\",\"authors\":\"J. Przybylo\",\"doi\":\"10.1002/rsa.21058\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The irregularity strength of a simple graph G=(V,E) , denoted s(G) is a certain measure of the level of irregularity of a graph. It indicates how hard it is to make an irregular multigraph of G via multiplication of its selected edges. It is however more commonly set forth through k‐weightings, that is, mappings ω:E→{1,2,…,k} , assigning every vertex v∈V the weighted degree σ(v):=∑e∋vω(e) . In this setting, s(G) is precisely defined as the least k admitting a k‐weighting of G which attributes pairwise distinct weighted degrees to all vertices of G. It is known that s(G)>n/d in the case of d‐regular graphs with order n and d>1 . An open conjecture of Faudree and Lehel from the 1980s states that s(G)≤n/d+c in turn for some finite constant c independent of d. It is believed that the natural strengthening of this conjecture toward all graphs where d is substituted by the minimum degree δ should also hold. We confirm this supposition in the case of random graphs. Namely, we show that asymptotically almost surely the generalization of Faudree‐Lehel Conjecture holds for a random graph G∈𝒢(n,p) for any constant p, that is, that s(G) takes one of the three values: ⌈n/δ⌉ , ⌈n/δ⌉+1 , or ⌈n/δ⌉+2 . This is implied by the fact that a.a.s. p−1\",\"PeriodicalId\":54523,\"journal\":{\"name\":\"Random Structures & Algorithms\",\"volume\":\"5 1\",\"pages\":\"383 - 396\"},\"PeriodicalIF\":0.9000,\"publicationDate\":\"2021-11-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Random Structures & Algorithms\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1002/rsa.21058\",\"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}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Random Structures & Algorithms","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1002/rsa.21058","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}
A generalization of Faudree–Lehel conjecture holds almost surely for random graphs
The irregularity strength of a simple graph G=(V,E) , denoted s(G) is a certain measure of the level of irregularity of a graph. It indicates how hard it is to make an irregular multigraph of G via multiplication of its selected edges. It is however more commonly set forth through k‐weightings, that is, mappings ω:E→{1,2,…,k} , assigning every vertex v∈V the weighted degree σ(v):=∑e∋vω(e) . In this setting, s(G) is precisely defined as the least k admitting a k‐weighting of G which attributes pairwise distinct weighted degrees to all vertices of G. It is known that s(G)>n/d in the case of d‐regular graphs with order n and d>1 . An open conjecture of Faudree and Lehel from the 1980s states that s(G)≤n/d+c in turn for some finite constant c independent of d. It is believed that the natural strengthening of this conjecture toward all graphs where d is substituted by the minimum degree δ should also hold. We confirm this supposition in the case of random graphs. Namely, we show that asymptotically almost surely the generalization of Faudree‐Lehel Conjecture holds for a random graph G∈𝒢(n,p) for any constant p, that is, that s(G) takes one of the three values: ⌈n/δ⌉ , ⌈n/δ⌉+1 , or ⌈n/δ⌉+2 . This is implied by the fact that a.a.s. p−1
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.