Results 31 to 40 of about 2,447 (140)

On distance signless Laplacian spectrum and energy of graphs

open access: yesElectronic Journal of Graph Theory and Applications, 2018
The distance signless Laplacian spectral radius of a connected graph G is the largest eigenvalue of the distance signless Laplacian matrix of G‎, ‎defined as ‎D‎Q(G) = Tr(G) + D(G)‎, ‎where D(G) is the distance matrix of G and Tr(G) is the diagonal ...
Abdollah Alhevaz   +2 more
doaj   +1 more source

On Distance Signless Laplacian Spectral Radius and Distance Signless Laplacian Energy

open access: yesMathematics, 2020
In this article, we find sharp lower bounds for the spectral radius of the distance signless Laplacian matrix of a simple undirected connected graph and we apply these results to obtain sharp upper bounds for the distance signless Laplacian energy graph.
Luis Medina, Hans Nina, Macarena Trigo
doaj   +1 more source

The sum of the largest and smallest signless laplacian eigenvalues and some Hamiltonian properties of graphs

open access: yesCommunications in Advanced Mathematical Sciences, 2018
The signless Laplacian eigenvalues of a graph $G$ are eigenvalues of the matrix $Q(G) = D(G) + A(G)$, where $D(G)$ is the diagonal matrix of the degrees of the vertices in $G$ and $A(G)$ is the adjacency matrix of $G$.
Rao Li
doaj   +1 more source

Topological Indices of Certain Transformed Chemical Structures

open access: yesJournal of Chemistry, Volume 2020, Issue 1, 2020., 2020
Topological indices like generalized Randić index, augmented Zagreb index, geometric arithmetic index, harmonic index, product connectivity index, general sum‐connectivity index, and atom‐bond connectivity index are employed to calculate the bioactivity of chemicals.
Xuewu Zuo   +5 more
wiley   +1 more source

The signless Laplacian matrix of hypergraphs

open access: yesSpecial Matrices, 2022
In this article, we define signless Laplacian matrix of a hypergraph and obtain structural properties from its eigenvalues. We generalize several known results for graphs, relating the spectrum of this matrix to structural parameters of the hypergraph ...
Cardoso Kauê, Trevisan Vilmar
doaj   +1 more source

A Note on Some Bounds of the α‐Estrada Index of Graphs

open access: yesAdvances in Mathematical Physics, Volume 2020, Issue 1, 2020., 2020
Let G be a simple graph with n vertices. Let A~αG=αDG+1−αAG, where 0 ≤ α ≤ 1 and A(G) and D(G) denote the adjacency matrix and degree matrix of G, respectively. EEαG=∑i=1neλi is called the α‐Estrada index of G, where λ1, ⋯, λn denote the eigenvalues of A~αG. In this paper, the upper and lower bounds for EEα(G) are given.
Yang Yang   +3 more
wiley   +1 more source

A Sharp upper bound for the spectral radius of a nonnegative matrix and applications [PDF]

open access: yes, 2016
In this paper, we obtain a sharp upper bound for the spectral radius of a nonnegative matrix. This result is used to present upper bounds for the adjacency spectral radius, the Laplacian spectral radius, the signless Laplacian spectral radius, the ...
Shu, Yujie, You, Lihua, Zhang, Xiao-Dong
core   +2 more sources

Construction for the Sequences of Q‐Borderenergetic Graphs

open access: yesMathematical Problems in Engineering, Volume 2020, Issue 1, 2020., 2020
This research intends to construct a signless Laplacian spectrum of the complement of any k‐regular graph G with order n. Through application of the join of two arbitrary graphs, a new class of Q‐borderenergetic graphs is determined with proof. As indicated in the research, with a regular Q‐borderenergetic graph, sequences of regular Q‐borderenergetic ...
Bo Deng   +4 more
wiley   +1 more source

Aα‐Spectral Characterizations of Some Joins

open access: yesJournal of Mathematics, Volume 2020, Issue 1, 2020., 2020
Let G be a graph with n vertices. For every real α ∈ [0,1], write Aα(G) for the matrix Aα(G) = αD(G) + (1 − α)A(G), where A(G) and D(G) denote the adjacency matrix and the degree matrix of G, respectively. The collection of eigenvalues of Aα(G) together with multiplicities are called the Aα‐spectrum of G.
Tingzeng Wu, Tian Zhou, Naihuan Jing
wiley   +1 more source

Spectral properties of the commuting graphs of certain groups

open access: yesAKCE International Journal of Graphs and Combinatorics, 2019
Let G be a finite group. The commuting graph Γ=C(G)is a simple graph with vertex set G and two vertices are adjacent if and only if they commute with each other.
M. Torktaz, A.R. Ashrafi
doaj   +1 more source

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