Results 1 to 10 of about 31,573 (274)

Elusive extremal graphs [PDF]

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 ...
Grzesik, Andrzej, Král', Daniel, Lovász, László Miklós   +2 more
core   +8 more sources

Extremal Optimization for Graph Partitioning [PDF]

Physical Review E, 2001
Extremal optimization is a new general-purpose method for approximating solutions to hard optimization problems. We study the method in detail by way of the NP-hard graph partitioning problem.
A. K. Hartmann, A. Möbius, Allon G. Percus, B. A. Hendrickson, B. Bollobas, C. J. Alpert, D. R. Chialvo, D. S. Johnson, D. S. Johnson, E. Tuzel, G. Ausiello, G. S. Grest, G. Toulouse, H. Frauenkron, I. Balberg, J. Holland, J. R. Banavar, K. F. Pal, K. Y. M. Wong, K. Y. M. Wong, M. Mezard, M. Mezard, M. Paczuski, M. Palassini, M. R. Garey, P. Bak, P. Bak, P. Cheeseman, P. Erdös, R. Monasson, R. Monasson, R. Monasson, S. Boettcher, S. Boettcher, S. Boettcher, S. Boettcher, S. Boettcher, S. Boettcher, S. Boettcher, S. J. Gould, S. Kirkpatrick, S. Kirkpatrick, Stefan Boettcher, T. Klotz, Y. T. Fu   +44 more
core   +3 more sources

Tight upper bound on the maximum anti-forcing numbers of graphs [PDF]

Discrete Mathematics & Theoretical Computer Science, 2017
Let $G$ be a simple graph with a perfect matching. Deng and Zhang showed that the maximum anti-forcing number of $G$ is no more than the cyclomatic number.
Lingjuan Shi, Heping Zhang
doaj   +3 more sources

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

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 K_(s,t)-free bipartite graphs [PDF]

Discrete Mathematics & Theoretical Computer Science, 2008
Graphs and ...
Camino Balbuena, P. García-Vázquez, Xavier Marcote, J. C. Valenzuela   +3 more
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

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, Peng Jiarong, Chen Tianyuan   +2 more
doaj   +1 more source