Results 11 to 20 of about 140 (117)
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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Inequalities for Distance Signless Laplacian Matrix Under Minimum-Degree Constraints
Journal of MathematicsFor a connected graph G of order n, let DG denote its distance matrix and let TrG be the diagonal matrix formed by the vertex transmissions. The distance signless Laplacian of G is defined by DQ=DG+TrG.
Mohd Abrar Ul Haq, S. Pirzada, Y. Shang
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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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The smallest spectral radius of graphs with a given clique number. [PDF]
ScientificWorldJournal, 2014 The first four smallest values of the spectral radius among all connected graphs with maximum clique size ω ≥ 2 are obtained.
Zhang JM, Huang TZ, Guo JM.
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New Bounds for the Generalized Distance Spectral Radius/Energy of Graphs
Mathematical Problems in Engineering, Volume 2022, Issue 1, 2022., 2022 Let G be a simple connected graph with vertex set V(G) = {v1, v2, …, vn} and dvi be the degree of the vertex vi. Let D(G) be the distance matrix and Tr(G) be the diagonal matrix of the vertex transmissions of G. The generalized distance matrix of G is defined as Dα(G) = αTr(G) + (1 − α)D(G), where 0 ≤ α ≤ 1. If λ1, λ2, …, λn are the eigenvalues of Dα(G)
Yuzheng Ma +3 more
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Sufficient Conditions for Graphs to Be k‐Connected, Maximally Connected, and Super‐Connected
Complexity, Volume 2021, Issue 1, 2021., 2021 Let G be a connected graph with minimum degree δ(G) and vertex‐connectivity κ(G). The graph G is k‐connected if κ(G) ≥ k, maximally connected if κ(G) = δ(G), and super‐connected if every minimum vertex‐cut isolates a vertex of minimum degree. In this paper, we present sufficient conditions for a graph with given minimum degree to be k‐connected ...
Zhen-Mu Hong +4 more
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Hamilton Connectivity of Convex Polytopes with Applications to Their Detour Index
Complexity, Volume 2021, Issue 1, 2021., 2021 A connected graph is called Hamilton‐connected if there exists a Hamiltonian path between any pair of its vertices. Determining whether a graph is Hamilton‐connected is an NP‐complete problem. Hamiltonian and Hamilton‐connected graphs have diverse applications in computer science and electrical engineering.
Sakander Hayat +4 more
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The Randić index and signless Laplacian spectral radius of graphs [PDF]
Discrete Mathematics, 2019 Given a connected graph $G$, the Randić index $R(G)$ is the sum of $\tfrac{1}{\sqrt{d(u)d(v)}}$ over all edges $\{u,v\}$ of $G$, where $d(u)$ and $d(v)$ are the degree of vertices $u$ and $v$ respectively. Let $q(G)$ be the largest eigenvalue of the singless Laplacian matrix of $G$ and $n=|V(G)|$. Hansen and Lucas (2010) made the following conjecture: \
Bo Ning 0001, Xing Peng
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Some Chemistry Indices of Clique‐Inserted Graph of a Strongly Regular Graph
Complexity, Volume 2021, Issue 1, 2021., 2021 In this paper, we give the relation between the spectrum of strongly regular graph and its clique‐inserted graph. The Laplacian spectrum and the signless Laplacian spectrum of clique‐inserted graph of strongly regular graph are calculated. We also give formulae expressing the energy, Kirchoff index, and the number of spanning trees of clique‐inserted ...
Chun-Li Kan +4 more
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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.
Das, Kinkar Ch., Liu, Muhuo
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