Results 11 to 20 of about 960 (155)
Spectral Sufficient Conditions on Pancyclic Graphs
Complexity, 2021 A pancyclic graph of order n is a graph with cycles of all possible lengths from 3 to n. In fact, it is NP-complete that deciding whether a graph is pancyclic.
Guidong Yu +3 more
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On Extremal Spectral Radii of Uniform Supertrees with Given Independence Number
Discrete Dynamics in Nature and Society, 2022 A supertree is a connected and acyclic hypergraph. Denote by Tm,n,α the set of m-uniform supertrees of order n with independent number α. Focusing on the spectral radius in Tm,n,α, this present completely determines the hypergraphs with maximum spectral ...
Lei Zhang, Haizhen Ren
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Signless Laplacian spectral radius and fractional matchings in graphs [PDF]
, 2017 A {\it fractional matching} of a graph $G$ is a function $f$ giving each edge a number in $[0,1]$ so that $\sum_{e\in (v)}f(e)\leq 1$ for each $v\in V(G)$, where $ (v)$ is the set of edges incident to $v$. The {\it fractional matching number} of $G$, written $ '_{*}(G)$, is the maximum of $\sum_{e\in E(G)}f(e)$ over all fractional matchings $f$. In
Ruifang Liu, Yu Lu
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Signless Laplacian spectral radius for a k-extendable graph [PDF]
Filomat, 2023 Let k and n be two nonnegative integers with n ? 0 (mod 2), and let G be a graph of order n with a perfect matching. Then G is said to be k-extendable for 0 ? k ? n?2/2 if every matching in G of size k can be extended to a perfect matching. In this paper, we first establish a lower bound on the signless Laplacian spectral radius of G to ensure that G ...
Sizhong Zhou, Yuli Zhang
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Quotient of spectral radius, (signless) Laplacian spectral radius and clique number of graphs [PDF]
Czechoslovak Mathematical Journal, 2016 The author gives sharp lower and upper bounds for the ratio of adjacency spectral radius and the clique number and the ratio of signless Laplacian spectral radius and the clique number, together with characterisation of extremal graphs. These results prove a conjecture from [\textit{M.
Kinkar Chandra Das, Muhuo Liu
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Signless Laplacian Spectral Conditions for Hamiltonicity of Graphs
Journal of Applied Mathematics, 2014 We establish some signless Laplacian spectral radius conditions for a graph to be Hamiltonian or traceable or Hamilton-connected.
Guidong Yu +3 more
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Distance signless Laplacian spectral radius and Hamiltonian properties of graphs [PDF]
Linear and Multilinear Algebra, 2016 In this paper, first, we establish a sufficient condition for a bipartite graph to be Hamilton-connected. Furthermore, we also give two sufficient conditions on distance signless Laplacian spectral radius for a graph to be Hamilton-connected and traceable from every vertex, respectively.
Qiannan Zhou, Ligong Wang
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Signless Laplacian spectral radius and fractional matchings in graphs [PDF]
Discrete Mathematics, 2020 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Yingui Pan, Jianping Li, Wei Zhao
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Sharp Bounds for the Signless Laplacian Spectral Radius in Terms of Clique Number [PDF]
, 2012 In this paper, we present a sharp upper and lower bounds for the signless Laplacian spectral radius of graphs in terms of clique number. Moreover, the extremal graphs which attain the upper and lower bounds are characterized.
Bian He, Ya-Lei Jin, Xiao‐Dong Zhang
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On the Signless Laplacian Spectral Radius of Cacti
Croatica Chemica Acta, 2016 A cactus is a connected graph in which any two cycles have at most one vertex in common. We determine the unique graphs with maximum signless Laplacian spectral radius in the class of cacti with given number of cycles (cut edges, respectively) as well as in the class of cacti with perfect matchings and given number of cycles.
Mingzhu Chen, Bo Zhou
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