Results 21 to 30 of about 31,573 (274)
The maximum number of $P_\ell$ copies in $P_k$-free graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2019 Generalizing Tur\'an's classical extremal problem, Alon and Shikhelman investigated the problem of maximizing the number of $T$ copies in an $H$-free graph, for a pair of graphs $T$ and $H$.
Ervin Győri +3 more
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Extremal $H$-Free Planar Graphs
The Electronic Journal of Combinatorics, 2019 Given a graph $H$, a graph is $H$-free if it does not contain $H$ as a subgraph. We continue to study the topic of "extremal" planar graphs initiated by Dowden [J. Graph Theory 83 (2016) 213–230], that is, how many edges can an $H$-free planar graph on $n$ vertices have?
Yongxin Lan, Yongtang Shi, Zi-Xia Song
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On some interconnections between combinatorial optimization and extremal graph theory [PDF]
Yugoslav Journal of Operations Research, 2004 The uniting feature of combinatorial optimization and extremal graph theory is that in both areas one should find extrema of a function defined in most cases on a finite set.
Cvetković Dragoš M. +2 more
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A Class of Fibonacci Matrices, Graphs, and Games
Mathematics, 2022 In this paper, we define a class of Fibonacci graphs as graphs whose adjacency matrices are obtained by alternating binary Fibonacci words. We show that Fibonacci graphs are close in size to Turán graphs and that their size-stability tradeoff defined as ...
Valentin E. Brimkov, Reneta P. Barneva
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Extremal Optimization at the Phase Transition of the 3-Coloring Problem [PDF]
, 2004 We investigate the phase transition of the 3-coloring problem on random graphs, using the extremal optimization heuristic. 3-coloring is among the hardest combinatorial optimization problems and is closely related to a 3-state anti-ferromagnetic Potts ...
Allon G. Percus +12 more
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Extremal problems of double stars [PDF]
Discrete Mathematics & Theoretical Computer Science, 2023 In a generalized Tur\'an problem, two graphs $H$ and $F$ are given and the question is the maximum number of copies of $H$ in an $F$-free graph of order $n$. In this paper, we study the number of double stars $S_{k,l}$ in triangle-free graphs.
Ervin Győri +2 more
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Discrete Applied Mathematics, 2013 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
LeSaulnier, Timothy D., West, Douglas B.
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Extremal Permanents of Laplacian Matrices of Unicyclic Graphs
AxiomsThe extremal problem of Laplacian permanents of graphs is a classical and challenging topic in algebraic combinatorics, where the inherent #P-complete complexity of permanent computation renders this pursuit particularly intractable.
Tingzeng Wu +2 more
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Spectral radius and extremal graphs for class of unicyclic graph with pendant vertices
Advances in Mechanical Engineering, 2017 In this article, we research on the spectral radius of extremal graphs for the unicyclic graphs with girth g mainly by the graft transformation and matching and obtain the upper bounds of the spectral radius of unicyclic graphs.
Lu Zhi +5 more
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Ars Mathematica Contemporanea, 2012 A graph G is singular if the zero-one adjacency matrix has the eigenvalue zero. The multiplicity of the eigenvalue zero is called the nullity of G . For two vertices y and z of G , we call ( G , y , z ) a device with respect to y and z .
Irene Sciriha +4 more
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