Results 1 to 10 of about 999 (266)
On Eccentricity Version of Zagreb Coindices [PDF]
Mathematics Interdisciplinary Research, 2021 The eccentric connectivity coindex has recently been introduced (Hua and Miao, 2019) as the total eccentricity sum of all pairs of non-adjacent vertices in a graph.
Mahdieh Azari
doaj +1 more source
Proceedings of the London Mathematical Society, 2020 We study the uniqueness of optimal solutions to extremal graph theory problems. Lovasz conjectured that every finite feasible set of subgraph density constraints can be extended further by a finite set of density constraints so that the resulting set is satisfied by an asymptotically unique graph.
Grzesik, Andrzej +2 more
openaire +7 more sources
Capture-Time Extremal Cop-Win Graphs
Discussiones Mathematicae Graph Theory, 2021 We investigate extremal graphs related to the game of Cops and Robbers. We focus on graphs where a single cop can catch the robber; such graphs are called cop-win.
Offner David, Ojakian Kerry
doaj +1 more source
Construction Algorithm of Given Girth Graphs Based on Quantum Evolution [PDF]
Jisuanji gongcheng, 2017 To construct an extremal graph with a given girth is still a challenging problem of graph theory.Especially when the vertex number increasex combination explosion will appear.Thus,this paper proposes an algorithm for constructing graphs with given girth ...
FENG Xiaohua,SUN Yongqi
doaj +1 more source
Extremal properties of distance-based graph invariants for $k$-trees [PDF]
Mathematica Bohemica, 2018 Sharp bounds on some distance-based graph invariants of $n$-vertex $k$-trees are established in a unified approach, which may be viewed as the weighted Wiener index or weighted Harary index.
Minjie Zhang, Shuchao Li
doaj +1 more source
Extremal K_(s,t)-free bipartite graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2008 Graphs and ...
Camino Balbuena +3 more
doaj +1 more source
On the Boundary of Incidence Energy and Its Extremum Structure of Tricycle Graphs
Frontiers in Physics, 2020 With the wide application of graph theory in circuit layout, signal flow chart and power system, more and more attention has been paid to the network topology analysis method of graph theory.
Hongyan Lu, Zhongxun Zhu
doaj +1 more source
The Aα-spectral radius of complements of bicyclic and tricyclic graphs with n vertices
Special Matrices, 2021 Recently, the extremal problem of the spectral radius in the class of complements of trees, unicyclic graphs, bicyclic graphs and tricyclic graphs had been studied widely.
Chen Chaohui +2 more
doaj +1 more source
Extremal Graphs for Sombor Index with Given Parameters
Axioms, 2023 In this paper, we present the upper and lower bounds on Sombor index SO(G) among all connected graphs (respectively, connected bipartite graphs). We give some sharp lower and upper bounds on SO(G) among connected graphs in terms of some parameters ...
Wanping Zhang, Jixiang Meng, Na Wang
doaj +1 more source
On the Signless Laplacian Spectral Radius of Graphs without Small Books and Intersecting Quadrangles
Mathematics, 2022 In this paper, we determine the maximum signless Laplacian spectral radius of all graphs which do not contain small books as a subgraph and characterize all extremal graphs. In addition, we give an upper bound of the signless Laplacian spectral radius of
Ming-Zhu Chen +3 more
doaj +1 more source