Results 61 to 70 of about 279 (161)

On the Laplacian index of tadpole graphs

Special Matrices
In this article, we study the Laplacian index of tadpole graphs, which are unicyclic graphs formed by adding an edge between a cycle Ck{C}_{k} and a path Pn{P}_{n}.
Braga Rodrigo O., Veloso Bruno S.
doaj   +1 more source

Hardness Results and Spectral Techniques for Combinatorial Problems on Circulant Graphs [PDF]

, 1998
We show that computing (and even approximating) MAXIMUM CLIQUE and MINIMUM GRAPH COLORING for circulant graphs is essentially as hard as in the general case.
Ivan Gerace, Sebastiano Vigna, I. Gerace, S. Vigna, Bruno Codenotti, Codenotti, Bruno, Gerace, Ivan, Vigna, Sebastiano, B. Codenotti   +8 more
core   +1 more source

What is a proper graph Laplacian? An operator-theoretic framework for graph diffusion

Special Matrices
We introduce an operator-theoretic definition of a proper graph Laplacian as any matrix associated with a given graph that can be expressed as the composition of a divergence and a gradient operator, with the gradient acting between graph-related spaces ...
Estrada Ernesto
doaj   +1 more source

On applications of Andrica-Badea and Nagy inequalities in spectral graph theory [PDF]

, 2015
Applications of Andrica-Badea and Nagy inequalities for determining bounds of graph invariants of undirected, connected graphs are investigated. We consider bounds of the following invariants: the first Zagreb index, general Randic index, Laplacian ...
MILOVANOVIĆ, Igor, MILOVANOVIĆ, Emina, GLOGIĆ, Edin   +2 more
core  

Minimal driver sets on path and cycle graphs with arbitrary non-zero weights [PDF]

, 2022
Let $G$ be a simple, undirected graph on the vertex set $V=\{1,2,\ldots ,n\}$ and let $A$ be the adjacency matrix of $G.$ A non-empty subset $ \{i_{1},i_{2},\ldots ,i_{k}\}$ of $V$ is called a driver set for $G$ if the system $\mathbf{\dot{x}}=A\mathbf{x}
Maks, Johannes G.
core  

Some results involving the Aα-eigenvalues for graphs and line graphs

Special Matrices
Let GG be a simple graph with adjacency matrix A(G)A\left(G), degree diagonal matrix D(G),D\left(G), and let l(G)l\left(G) be the line graph of GG. In 2017, Nikiforov defined the Aα{A}_{\alpha }-matrix of GG, Aα(G){A}_{\alpha }\left(G), as a linear ...
da Silva Júnior João Domingos G., Oliveira Carla Silva, da Costa Liliana Manuela G. C.   +2 more
doaj   +1 more source

Revisiting hypergraph models for sparse matrix partitioning [PDF]

, 2006
. We provide an exposition of hypergraph models for parallelizing sparse matrix-vector multiplies. Our aim is to emphasize the expressive power of hypergraph models.
Uçar, Bora, Cevdet Aykanat, Bora Uçar, Uçar, B., Aykanat, Cevdet   +4 more
core   +1 more source

Signless Laplacian characterization of cones over disjoint unions of cycles, edges and isolated vertices

Special Matrices
Two graphs are said to be Q-cospectral if they share the same signless Laplacian spectrum. A simple graph is said to be determined by its signless Laplacian spectrum (abbreviated as DQS) if there exists no other non-isomorphic simple graph with the same ...
Ye Jiachang, Qian Jianguo, Stanić Zoran
doaj   +1 more source

Enumeration of Cospectral Graphs [PDF]

AMS classification: 05C50;graphs;eigenvalues ...
Spence, E., Haemers, W.H.
core  

Maximal Green Sequences of Exceptional Finite Mutation Type Quivers? [PDF]

, 2014
. Maximal green sequences are particular sequences of mutations of quivers which were introduced by Keller in the context of quantum dilogarithm identities and in-dependently by Cecotti–Córdova–Vafa in the context of supersymmetric gauge theory.
Seven, Ahmet İrfan, Ahmet I. Seven, Ahmet I. Seven, Seven, A.I.   +3 more
core   +1 more source