Journal of Graph Theory最新文献
筛选
英文
中文
On the Hardness of Switching to a Small Number of Edges
关于切换到少量边的硬度
IF 1
3区 数学
Vít Jelínek, Eva Jelínková, Jan Kratochvíl
{"title":"On the Hardness of Switching to a Small Number of Edges","authors":"Vít Jelínek, Eva Jelínková, Jan Kratochvíl","doi":"10.1002/jgt.70063","DOIUrl":"https://doi.org/10.1002/jgt.70063","url":null,"abstract":"<p>Seidel's switching is a graph operation which makes a given vertex adjacent to precisely those vertices to which it was non-adjacent before, while keeping the rest of the graph unchanged. Two graphs are called switching-equivalent if one can be made isomorphic to the other one by a sequence of switches. Jelínková et al. [DMTCS 13, no. 2, 2011] presented a proof that it is NP-complete to decide whether the input graph is switching-equivalent to a graph that contains at most a given number of edges. There turns out to be a flaw in their proof. We present a correct proof. Furthermore, we prove that the problem remains NP-complete even when restricted to graphs whose density is bounded from above by an arbitrary fixed constant. This partially answers a question of Matoušek and Wagner [Discrete Comput. Geom. 52, no. 1, 2014].</p>","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 2","pages":"237-251"},"PeriodicalIF":1.0,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jgt.70063","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148704255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Normal Approximation for Subgraph Count in Random Hypergraphs
随机超图中子图计数的正态逼近
IF 1
3区 数学
Mikołaj Nieradko, Wojciech Michalczuk, Grzegorz Serafin
{"title":"Normal Approximation for Subgraph Count in Random Hypergraphs","authors":"Mikołaj Nieradko, Wojciech Michalczuk, Grzegorz Serafin","doi":"10.1002/jgt.70066","DOIUrl":"https://doi.org/10.1002/jgt.70066","url":null,"abstract":"<div>\u0000 \u0000 <p>A nonuniform and inhomogeneous random hypergraph model is considered, which is a straightforward extension of the celebrated binomial random graph model <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mi>n</mi>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>p</mi>\u0000 </mrow>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> <math xmlns=\"http://www.w3.org/1998/Math/MathML\" altimg=\"urn:x-wiley:03649024:media:jgt70066:jgt70066-math-0001\" wiley:location=\"equation/jgt70066-math-0001.png\"><mrow><mrow><mi mathvariant=\"double-struck\">G</mi><mrow><mo>(</mo><mrow><mi>n</mi><mo>,</mo><mi>p</mi></mrow><mo>)</mo></mrow></mrow></mrow></math></annotation>\u0000 </semantics></math>. We establish necessary and sufficient conditions for the small hypergraph count to be asymptotically normal, and complement them with convergence rates in both the Wasserstein and Kolmogorov distances. Next we narrow our attention to the homogeneous model and relate the obtained results to the fourth moment phenomenon. Additionally, a short proof of the necessity of the aforementioned conditions is presented, which seems to be absent in the literature, even in the context of the model <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mi>n</mi>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>p</mi>\u0000 </mrow>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> <math xmlns=\"http://www.w3.org/1998/Math/MathML\" altimg=\"urn:x-wiley:03649024:media:jgt70066:jgt70066-math-0002\" wiley:location=\"equation/jgt70066-math-0002.png\"><mrow><mrow><mi mathvariant=\"double-struck\">G</mi><mrow><mo>(</mo><mrow><mi>n</mi><mo>,</mo><mi>p</mi></mrow><mo>)</mo></mrow></mrow></mrow></math></annotation>\u0000 </semantics></math>.</p>\u0000 </div>","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 2","pages":"311-347"},"PeriodicalIF":1.0,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148704301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
B-Coloring of Planar Graphs
平面图的b -着色
IF 1
3区 数学
Jiangxu Kong, Yiqiao Wang, Mengmeng Zheng
{"title":"B-Coloring of Planar Graphs","authors":"Jiangxu Kong, Yiqiao Wang, Mengmeng Zheng","doi":"10.1002/jgt.70067","DOIUrl":"https://doi.org/10.1002/jgt.70067","url":null,"abstract":"<div>\u0000 \u0000 <p>Let <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>q</mi>\u0000 \u0000 <mi>B</mi>\u0000 </msub>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mi>G</mi>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> <math xmlns=\"http://www.w3.org/1998/Math/MathML\" altimg=\"urn:x-wiley:03649024:media:jgt70067:jgt70067-math-0001\" wiley:location=\"equation/jgt70067-math-0001.png\"><mrow><mrow><msub><mi>q</mi><mi>B</mi></msub><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow></mrow></mrow></math></annotation>\u0000 </semantics></math> denote the minimum number of colors needed to properly color the edges of a graph <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> <math xmlns=\"http://www.w3.org/1998/Math/MathML\" altimg=\"urn:x-wiley:03649024:media:jgt70067:jgt70067-math-0002\" wiley:location=\"equation/jgt70067-math-0002.png\"><mrow><mrow><mi>G</mi></mrow></mrow></math></annotation>\u0000 </semantics></math> such that every 4-cycle is colored with four different colors. Very recently, Gyárfás et al. [3] proved that <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>q</mi>\u0000 \u0000 <mi>B</mi>\u0000 </msub>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mi>G</mi>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 \u0000 <mo>≤</mo>\u0000 \u0000 <mn>2</mn>\u0000 \u0000 <mi>Δ</mi>\u0000 \u0000 <mo>+</mo>\u0000 \u0000 <mn>8</mn>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> <math xmlns=\"http://www.w3.org/1998/Math/MathML\" altimg=\"urn:x-wiley:03649024:media:jgt70067:jgt70067-math-0003\" wiley:location=\"equation/jgt70067-math-0003.png\"><mrow><mrow><msub><mi>q</mi><mi>B</mi></msub><mrow><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mo>unicode{x02264}</mo><mn>2</mn","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 2","pages":"274-285"},"PeriodicalIF":1.0,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148704437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Turán Problems for Suspension of a Balanced Tree
Turán平衡树的悬挂问题
IF 1
3区 数学
Xiutao Zhu, Xiaolin Wang, Yanbo Zhang, Fangfang Zhang
{"title":"Turán Problems for Suspension of a Balanced Tree","authors":"Xiutao Zhu, Xiaolin Wang, Yanbo Zhang, Fangfang Zhang","doi":"10.1002/jgt.70053","DOIUrl":"https://doi.org/10.1002/jgt.70053","url":null,"abstract":"<div>\u0000 \u0000 <p>The Turán number <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mtext>ex</mtext>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mi>n</mi>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>H</mi>\u0000 </mrow>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> is the maximum number of edges that an <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>n</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-vertex <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>H</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-free graph can have. The suspension <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mover>\u0000 <mi>H</mi>\u0000 \u0000 <mo>^</mo>\u0000 </mover>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> is obtained from <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>H</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> by adding a new vertex which is adjacent to all vertices of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>H</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> and a tree <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>T</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> is balanced if the size of one color class is <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> and the other is <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> or <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 ","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 1","pages":"61-72"},"PeriodicalIF":1.0,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148522738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Orientations of Graphs With at Most One Directed Path Between Every Pair of Vertices
每对顶点之间最多有一条有向路径的图的方向
IF 1
3区 数学
Barbora Dohnalová, Jiří Kalvoda, Gaurav Kucheriya, Sophie Spirkl
{"title":"Orientations of Graphs With at Most One Directed Path Between Every Pair of Vertices","authors":"Barbora Dohnalová, Jiří Kalvoda, Gaurav Kucheriya, Sophie Spirkl","doi":"10.1002/jgt.70060","DOIUrl":"https://doi.org/10.1002/jgt.70060","url":null,"abstract":"<p>Given a graph <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, we say that an orientation <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>D</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> is a <i>KT orientation</i> if, for all <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>u</mi>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>v</mi>\u0000 \u0000 <mo>∈</mo>\u0000 \u0000 <mi>V</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mi>D</mi>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, there is at most one directed path (in any direction) between <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>u</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>v</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>. Graphs that admit such orientations have been used to construct graphs with large chromatic number and small clique number that served as counterexamples to various conjectures. Motivated by this, we consider which graphs admit KT orientations (named after Kierstead and Trotter). In particular, we construct a graph family with small independence number (sub-linear in the number of vertices) which admits a KT orientation. We show that the problem of determining whether a given graph admits a KT orientation is NP-complete, even if we restrict ourselves to planar graphs. Finally, we provide an algorithm to decide if a graph with maximum degree at most 3 admits a KT orientation, whereas, for graphs with maximum degree 4, the problem remains NP-complete.</p>","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 1","pages":"143-164"},"PeriodicalIF":1.0,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jgt.70060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148532871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Signed Projective Cubes, a Homomorphism Point of View
有符号射影立方体，一个同态的观点
IF 1
3区 数学
Meirun Chen, Reza Naserasr, Alessandra Sarti
{"title":"Signed Projective Cubes, a Homomorphism Point of View","authors":"Meirun Chen, Reza Naserasr, Alessandra Sarti","doi":"10.1002/jgt.70046","DOIUrl":"https://doi.org/10.1002/jgt.70046","url":null,"abstract":"<p>The (signed) projective cubes, as a special class of graphs closely related to the hypercubes, are on the crossroad of geometry, algebra, discrete mathematics and linear algebra. Defined as Cayley graphs on binary groups, they represent basic linear dependencies. Capturing the four-color theorem as a homomorphism target they show how mapping of discrete objects, namely graphs, may relate to special mappings of plane to projective spaces of higher dimensions. In this work, viewed as a signed graph, first we present a number of equivalent definitions each of which leads to a different development. In particular, the new notion of common product of signed graphs is introduced which captures both Cartesian and tensor products of graphs. With a nonstandard use of homomorphism between signed projective cubes, we show that they all have circular chromatic number 4. Observing that the 4-color theorem is about mapping planar graphs into <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>S</mi>\u0000 \u0000 <mi>P</mi>\u0000 \u0000 <mi>C</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mn>2</mn>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, we study some conjectures in extension of 4CT and show the importance of extended double cover operation in formulating such conjectures. As a particular corollary we build a highly symmetric triangle-free graph on 12 vertices admitting a homomorphism from every planar graph of odd girth at least 7. Considering their connection to algebraic geometry, we observe that <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>P</mi>\u0000 \u0000 <mi>C</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mn>4</mn>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, widely known as the Clebsh graph, also known as Greenwood-Gleason graph, is the intersection graph of the 16 straight lines of an algebraic surface known as Segre surface, which is a Del Pezzo surface of degree 4. Noting that the Clebsch surface is one of the most symmetric presentations of a cubic surface all of which contains 27 lines. Hence, from hereafter, we believe, a proper name for <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 ","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 1","pages":"38-56"},"PeriodicalIF":1.0,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jgt.70046","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148534208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Counterexamples to Two Conjectures on Mean Color Numbers of Graphs
关于图平均色数的两个猜想的反例
IF 1
3区 数学
Wushuang Zhai, Yan Yang
{"title":"Counterexamples to Two Conjectures on Mean Color Numbers of Graphs","authors":"Wushuang Zhai, Yan Yang","doi":"10.1002/jgt.70050","DOIUrl":"https://doi.org/10.1002/jgt.70050","url":null,"abstract":"<div>\u0000 \u0000 <p>The mean color number of an <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>n</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-vertex graph <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, denoted by <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>μ</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mi>G</mi>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, is the average number of colors used in all proper <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>n</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-colorings of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>. For any graph <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> and any vertex <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>w</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> in <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, Dong (2003) conjectured that (1) <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>μ</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mi>G</mi>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 \u0000 <mo>≥</mo>\u0000 \u0000 <mi>μ</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mi>G</mi>\u0000 \u0000 ","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 1","pages":"57-60"},"PeriodicalIF":1.0,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148534401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Fractional Balanced Chromatic Number and Arboricity of Planar (Signed) Graphs
平面（符号）图的分数阶平衡色数与拟合性
IF 1
3区 数学
Reza Naserasr, Lan Anh Pham, Cyril Pujol, Huan Zhou
{"title":"Fractional Balanced Chromatic Number and Arboricity of Planar (Signed) Graphs","authors":"Reza Naserasr, Lan Anh Pham, Cyril Pujol, Huan Zhou","doi":"10.1002/jgt.70047","DOIUrl":"https://doi.org/10.1002/jgt.70047","url":null,"abstract":"<p>A balanced <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mi>p</mi>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>q</mi>\u0000 </mrow>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-coloring of a signed graph <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>σ</mi>\u0000 </mrow>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> is an assignment of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>q</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> colors to each vertex of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> from a platter of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>p</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> colors, such that each color class induces a balanced set (a set that does not induce a negative cycle). The fractional balanced chromatic number of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>σ</mi>\u0000 </mrow>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, denoted <span></span><","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 1","pages":"5-18"},"PeriodicalIF":1.0,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jgt.70047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148533882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On Tight Tree-Complete Hypergraph Ramsey Numbers
紧树-完全超图Ramsey数
IF 1
3区 数学
Jiaxi Nie
{"title":"On Tight Tree-Complete Hypergraph Ramsey Numbers","authors":"Jiaxi Nie","doi":"10.1002/jgt.70054","DOIUrl":"https://doi.org/10.1002/jgt.70054","url":null,"abstract":"<p>Chvátal showed that for any tree <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>T</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> edges, the Ramsey number <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>R</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mi>T</mi>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>n</mi>\u0000 </mrow>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 \u0000 <mo>=</mo>\u0000 \u0000 <mi>k</mi>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mrow>\u0000 <mi>n</mi>\u0000 \u0000 <mo>−</mo>\u0000 \u0000 <mn>1</mn>\u0000 </mrow>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 \u0000 <mo>+</mo>\u0000 \u0000 <mn>1</mn>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>. For <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>r</mi>\u0000 \u0000 <mo>=</mo>\u0000 \u0000 <mn>3</mn>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> or 4, we show that, if <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>T</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> is an <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>r</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-uniform nontrivial tight tree, then the hypergraph Ramsey number <span></span><math>\u0000 <semantics","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 1","pages":"88-96"},"PeriodicalIF":1.0,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jgt.70054","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148534358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Vertex-Distinguishing and Sum-Distinguishing Edge Coloring of Regular Graphs
正则图的点区分和区分边着色
IF 1
3区 数学
Yuping Gao, Songling Shan, Guanghui Wang
{"title":"Vertex-Distinguishing and Sum-Distinguishing Edge Coloring of Regular Graphs","authors":"Yuping Gao, Songling Shan, Guanghui Wang","doi":"10.1002/jgt.70049","DOIUrl":"https://doi.org/10.1002/jgt.70049","url":null,"abstract":"<div>\u0000 \u0000 <p>Given an integer <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 \u0000 <mo>≥</mo>\u0000 \u0000 <mn>1</mn>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>, an edge-<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-coloring of a graph <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> is an assignment of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> colors <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mn>1</mn>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mo>…</mo>\u0000 \u0000 <mo>,</mo>\u0000 \u0000 <mi>k</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> to the edges of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> such that no two adjacent edges receive the same color. A vertex-distinguishing (resp. sum-distinguishing) edge-<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-coloring of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> is an edge-<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>k</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math>-coloring such that for any two distinct vertices <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>u</mi>\u0000 </mrow>\u0000 </mrow>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>v</mi>","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"113 1","pages":"73-87"},"PeriodicalIF":1.0,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148534432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
影响因子
展开
类型
展开
期刊
展开
全部
Acc. Chem. Res.
ACS Applied Bio Materials
ACS Appl. Electron. Mater.
ACS Appl. Energy Mater.
ACS Appl. Mater. Interfaces
ACS Appl. Nano Mater.
ACS Appl. Polym. Mater.
ACS BIOMATER-SCI ENG
ACS Catal.
ACS Cent. Sci.
ACS Chem. Biol.
ACS Chemical Health & Safety
ACS Chem. Neurosci.
ACS Comb. Sci.
ACS Earth Space Chem.
ACS Energy Lett.
ACS Infect. Dis.
ACS Macro Lett.
ACS Mater. Lett.
ACS Med. Chem. Lett.
ACS Nano
ACS Omega
ACS Photonics
ACS Sens.
ACS Sustainable Chem. Eng.
ACS Synth. Biol.
Anal. Chem.
BIOCHEMISTRY-US
Bioconjugate Chem.
BIOMACROMOLECULES
Chem. Res. Toxicol.
Chem. Rev.
Chem. Mater.
CRYST GROWTH DES
ENERG FUEL
Environ. Sci. Technol.
Environ. Sci. Technol. Lett.
Eur. J. Inorg. Chem.
IND ENG CHEM RES
Inorg. Chem.
J. Agric. Food. Chem.
J. Chem. Eng. Data
J. Chem. Educ.
J. Chem. Inf. Model.
J. Chem. Theory Comput.
J. Med. Chem.
J. Nat. Prod.
J PROTEOME RES
J. Am. Chem. Soc.
LANGMUIR
MACROMOLECULES
Mol. Pharmaceutics
Nano Lett.
Org. Lett.
ORG PROCESS RES DEV
ORGANOMETALLICS
J. Org. Chem.
J. Phys. Chem.
J. Phys. Chem. A
J. Phys. Chem. B
J. Phys. Chem. C
J. Phys. Chem. Lett.
Analyst
Anal. Methods
Biomater. Sci.
Catal. Sci. Technol.
Chem. Commun.
Chem. Soc. Rev.
CHEM EDUC RES PRACT
CRYSTENGCOMM
Dalton Trans.
Energy Environ. Sci.
ENVIRON SCI-NANO
ENVIRON SCI-PROC IMP
ENVIRON SCI-WAT RES
Faraday Discuss.
Food Funct.
Green Chem.
Inorg. Chem. Front.
Integr. Biol.
J. Anal. At. Spectrom.
J. Mater. Chem. A
J. Mater. Chem. B
J. Mater. Chem. C
Lab Chip
Mater. Chem. Front.
Mater. Horiz.
MEDCHEMCOMM
Metallomics
Mol. Biosyst.
Mol. Syst. Des. Eng.
Nanoscale
Nanoscale Horiz.
Nat. Prod. Rep.
New J. Chem.
Org. Biomol. Chem.
Org. Chem. Front.
PHOTOCH PHOTOBIO SCI
PCCP
Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX
EndNote
RefMan
NoteFirst
NoteExpress
求助内容：
应助结果提醒方式：请完成安全验证×
京公网安备 11010802042870号
