Results 61 to 70 of about 110,880 (163)
Signless Laplacian eigenvalue problems of Nordhaus–Gaddum type [PDF]
Linear Algebra and its Applications, 2019 17 pages, 2 ...
Xueyi Huang, Huiqiu Lin
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Computing the reciprocal distance signless Laplacian eigenvalues and energy of graphs [PDF]
, 2019 In this paper, we study the eigenvalues of the reciprocal distance signless Laplacian matrix of a connected graph and obtain some bounds for the maximum eigenvalue of this matrix.
Ramane, Harishchandra +2 more
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Spectral Characterizations of the Aα−‐Matrix for Graph Products
International Journal of Mathematics and Mathematical Sciences, Volume 2026, Issue 1, 2026.For α ∈ [0, 1], the matrix Aα−G=αDG+α−1AG defines a Laplacian–type operator associated with a graph G, interpolating between −A(G) and D(G). In this paper, we develop a systematic study of the Aα−‐spectrum under several classical graph products.
Zakeiah Alkhamisi +4 more
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The spectral radius of signless Laplacian matrix and sum-connectivity index of graphs
AKCE International Journal of Graphs and Combinatorics, 2022 The sum-connectivity index of a graph G is defined as the sum of weights [Formula: see text] over all edges uv of G, where du and dv are the degrees of the vertices u and v in G, respectively.
A. Jahanbani, S. M. Sheikholeslami
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Inequalities for Distance Signless Laplacian Matrix Under Minimum‐Degree Constraints
Journal of Mathematics, Volume 2026, Issue 1, 2026.For a connected graph G of order n, let D(G) denote its distance matrix and let Tr(G) be the diagonal matrix formed by the vertex transmissions. The distance signless Laplacian of G is defined by DQ = D(G) + Tr(G). The largest eigenvalue of DQ, written as ∂1QG, is referred to as the distance signless Laplacian spectral radius of G.
Mohd Abrar Ul Haq +3 more
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The second least eigenvalue of the signless Laplacian of the complements of trees [PDF]
Electronic Journal of Graph Theory and Applications, 2019 Summary: Suppose that \(\mathfrak{T}_n^c\) is a set, such that the elements of \(\mathfrak{T}_n^c\) are the complements of trees of order \(n\). In 2012, Li and Wang gave the unique graph in the set \(\mathfrak{T}_n^c\setminus\{K_{1, n-1}\}\) with minimum 1st `least eigenvalue of the signless Laplacian' (abbreviated to a LESL).
Muhammad Ajmal +2 more
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Spectrum of the Cozero-Divisor Graph Associated to Ring
Axioms, 2023 Let R be a commutative ring with identity 1≠0 and let Z(R)′ be the set of all non-unit and non-zero elements of ring R. Γ′(R) denotes the cozero-divisor graph of R and is an undirected graph with vertex set Z(R)′, w∉zR, and z∉wR if and only if two ...
Mohd Rashid +3 more
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Refined Lower Bounds for the Laplacian Estrada Index of Connected Graphs via the Two Largest Degrees
Journal of Mathematics, Volume 2026, Issue 1, 2026.Let G be a graph with n vertices and Laplacian eigenvalues μ1, μ2, …, μn. The Laplacian Estrada index of G is defined as LEEG=eμ1+⋯+eμn. In this paper, using the Karush–Kuhn–Tucker optimization framework under inequality constraints, we establish new lower bounds for LEE(G) in terms of the two largest degrees of G.
Hamidreza Bamdad +3 more
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Construction of Albertson Cospectral and Albertson Equienergetic Graphs Using Graph Operations
Journal of Mathematics, Volume 2026, Issue 1, 2026.The energy of a graph is an invariant calculated as the sum of the absolute eigenvalues of its adjacency matrix. This concept extends to various types of energies derived from different graph‐related matrices. This paper explores the spectral properties of Albertson energy and Albertson spectra.
Jane Shonon Cutinha +3 more
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On two energy-like invariants of line graphs and related graph operations
Journal of Inequalities and Applications, 2016 For a simple graph G of order n, let μ 1 ≥ μ 2 ≥ ⋯ ≥ μ n = 0 $\mu_{1}\geq\mu_{2}\geq\cdots\geq\mu_{n}=0$ be its Laplacian eigenvalues, and let q 1 ≥ q 2 ≥ ⋯ ≥ q n ≥ 0 $q_{1}\geq q_{2}\geq\cdots\geq q_{n}\geq0$ be its signless Laplacian eigenvalues.
Xiaodan Chen, Yaoping Hou, Jingjian Li
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