Results 21 to 30 of about 517 (82)
The Generalized Distance Spectrum of the Join of Graphs [PDF]
, 2020 Let G be a simple connected graph. In this paper, we study the spectral properties of the generalized distance matrix of graphs, the convex combination of the symmetric distance matrix D(G) and diagonal matrix of the vertex transmissions Tr(G) .
Alhevaz, Abdollah +3 more
core +2 more sources
Maxima of the Q-index: graphs without long paths [PDF]
, 2013 This paper gives tight upper bound on the largest eigenvalue q(G) of the signless Laplacian of graphs with no paths of given order. The main ingredient of our proof is a stability result of its own interest, about graphs with large minimum degree and ...
Nikiforov, Vladimir, Yuan, Xiying
core +1 more source
New Notions and Constructions of Sparsification for Graphs and Hypergraphs [PDF]
, 2019 A sparsifier of a graph $G$ (Bencz\'ur and Karger; Spielman and Teng) is a sparse weighted subgraph $\tilde G$ that approximately retains the cut structure of $G$.
Bansal, Nikhil +2 more
core +4 more sources
Resistance Distance and Kirchhoff Index for a Class of Graphs
Mathematical Problems in Engineering, Volume 2018, Issue 1, 2018., 2018 Let G[F, Vk, Hv] be the graph with k pockets, where F is a simple graph of order n ≥ 1, Vk = {v1, v2, …, vk} is a subset of the vertex set of F, Hv is a simple graph of order m ≥ 2, and v is a specified vertex of Hv. Also let G[F, Ek, Huv] be the graph with k edge pockets, where F is a simple graph of order n ≥ 2, Ek = {e1, e2, …ek} is a subset of the ...
WanJun Yin +3 more
wiley +1 more source
Generalized Characteristic Polynomials of Join Graphs and Their Applications
Discrete Dynamics in Nature and Society, Volume 2017, Issue 1, 2017., 2017 The Kirchhoff index of G is the sum of resistance distances between all pairs of vertices of G in electrical networks. LEL(G) is the Laplacian‐Energy‐Like Invariant of G in chemistry. In this paper, we define two classes of join graphs: the subdivision‐vertex‐vertex join G1⊚G2 and the subdivision‐edge‐edge join G1⊝G2.
Pengli Lu +3 more
wiley +1 more source
No Laplacian Perfect State Transfer in Trees [PDF]
, 2014 We consider a system of qubits coupled via nearest-neighbour interaction governed by the Heisenberg Hamiltonian. We further suppose that all coupling constants are equal to $1$.
Coutinho, Gabriel, Liu, Henry
core +1 more source
Bounds on the Spectral Radius of a Nonnegative Matrix and Its Applications
Journal of Applied Mathematics, Volume 2016, Issue 1, 2016., 2016 We obtain the sharp bounds for the spectral radius of a nonnegative matrix and then obtain some known results or new results by applying these bounds to a graph or a digraph and revise and improve two known results.
Danping Huang, Lihua You, Ali R. Ashrafi
wiley +1 more source
On Generalized Distance Gaussian Estrada Index of Graphs [PDF]
, 2019 For a simple undirected connected graph G of order n, let D(G) , DL(G) , DQ(G) and Tr(G) be, respectively, the distance matrix, the distance Laplacian matrix, the distance signless Laplacian matrix and the diagonal matrix of the vertex transmissions of G.
Alhevaz, Abdollah +2 more
core +1 more source
On the eigenvalues of the distance signless Laplacian matrix of graphs
Proyecciones (Antofagasta)Let G be a connected graph and let DQ(G) be the distance signless Laplacian matrix of G with eigenvalues ρ1≥ ρ2≥…≥ ρn. The spread of the matrix DQ}(G) is defined as s(DQ(G)) := maxi,j| ρi-ρj| = ρ1- ρn. We derive new bounds for the distance signless Laplacian spectral radius ρ1 of G.
Akbar Jahanbani +3 more
openaire +1 more source
The Least Algebraic Connectivity of Graphs
Discrete Dynamics in Nature and Society, Volume 2015, Issue 1, 2015., 2015 The algebraic connectivity of a graph is defined as the second smallest eigenvalue of the Laplacian matrix of the graph, which is a parameter to measure how well a graph is connected. In this paper, we present two unique graphs whose algebraic connectivity attain the minimum among all graphs whose complements are trees, but not stars, and among all ...
Guisheng Jiang +3 more
wiley +1 more source