Search Results - "Vilmar Trevisan"

Characterization of digraphs with three complementarity eigenvalues by Bravo, Diego, Cubría, Florencia, Fiori, Marcelo, Trevisan, Vilmar

“…Given a digraph D , the complementarity spectrum of the digraph is defined as the set of complementarity eigenvalues of its adjacency matrix. This…”
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The signless Laplacian matrix of hypergraphs by Cardoso, Kauê, Trevisan, Vilmar

“…In this article, we define signless Laplacian matrix of a hypergraph and obtain structural properties from its eigenvalues. We generalize several known results…”
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On Quipus whose signless Laplacian index does not exceed 4.5 by Belardo, Francesco, Brunetti, Maurizio, Trevisan, Vilmar, Wang, Jianfeng

“…Hoffman and Smith proved that in a graph with maximum degree Δ if all edges are subdivided infinitely many times, then the largest eigenvalue, also called…”
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On the Sum of k Largest Laplacian Eigenvalues of a Graph and Clique Number by Ganie, Hilal A., Pirzada, S., Trevisan, Vilmar

“…For a simple graph G with order n and size m having Laplacian eigenvalues μ 1 , μ 2 , ⋯ , μ n - 1 , μ n = 0 , let S k ( G ) = ∑ i = 1 k μ i , be the sum of k…”
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Determining Graphs by the Complementary Spectrum by Pinheiro, Lucélia K., Souza, Bruna S., Trevisan, Vilmar

“…The complementary spectrum of a connected graph is the set of the complementary eigenvalues of the adjacency matrix of . In this note, we discuss the…”
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Independence and matching numbers of unicyclic graphs from null space by Allem, L. Emilio, Jaume, Daniel A., Molina, Gonzalo, Toledo, Maikon M., Trevisan, Vilmar

“…We characterize unicyclic graphs that are singular using the support of the null space of their pendant trees. From this, we obtain closed formulas for the…”
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Graphs sharing an arbitrary number of ordered complementarity eigenvalues by Sossa, David, Trevisan, Vilmar

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Brouwer's Conjecture for the Cartesian product of graphs by Torres, Guilherme Simon, Trevisan, Vilmar

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Limit points of (signless) Laplacian spectral radii of linear trees by Belardo, Francesco, Oliveira, Elismar R., Trevisan, Vilmar

“…We study limit points of the spectral radii of Laplacian matrices of graphs. We adapted the method used by J. B. Shearer in 1989, devised to prove the density…”
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Spectral threshold dominance, Brouwer's conjecture and maximality of Laplacian energy by Helmberg, Christoph, Trevisan, Vilmar

“…The Laplacian energy of a graph is the sum of the distances of the eigenvalues of the Laplacian matrix of the graph to the graph's average degree. The maximum…”
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Locating eigenvalues of unbalanced unicyclic signed graphs by Belardo, Francesco, Brunetti, Maurizio, Trevisan, Vilmar

“…•We provide an algorithm specialized to the class of unbalanced unicyclic signed graphs.•The algorithm computes the number of eigenvalues lying in a given real…”
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Eigenvalues and energy in threshold graphs by Jacobs, David P., Trevisan, Vilmar, Tura, Fernando

“…Assuming a uniform random model of selecting creation sequences, we show that almost every connected threshold graph has more negative than positive…”
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Complementary eigenvalues of graphs by Fernandes, Rafael, Judice, Joaquim, Trevisan, Vilmar

“…In this paper, we study the Eigenvalue Complementarity Problem (EiCP) when its matrix A belongs to the class S(G)={A=[aij]:aij=aji≠0 iff ij∈E}, where G=(V,E)…”
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Threshold graphs of maximal Laplacian energy by Helmberg, Christoph, Trevisan, Vilmar

“…The Laplacian energy of a graph is defined as the sum of the absolute values of the differences of average degree and eigenvalues of the Laplacian matrix of…”
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Eigenvalue location in threshold graphs by Jacobs, David P., Trevisan, Vilmar, Tura, Fernando

“…Let G be a threshold graph of order n with adjacency matrix A. We present an O(n) algorithm for constructing a diagonal matrix congruent to Bx=A+xI for any x…”
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A unified criterion for distinguishing graphs by their spectral radius by Merajuddin, S., Kumar, Pawan, Pirzada, S., Trevisan, Vilmar

“…Complementarity spectrum of a connected graph G, denoted by $ \Pi (G) $ Π ( G ) , is the set of spectral radii of all connected induced subgraphs of G…”
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Most Laplacian eigenvalues of a tree are small by Jacobs, David P., Oliveira, Elismar R., Trevisan, Vilmar

“…We show that the number of Laplacian eigenvalues less than the average degree 2−2n of a tree having n vertices is at least ⌈n2⌉…”
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Principal eigenvectors of general hypergraphs by Cardoso, Kauê, Trevisan, Vilmar

“…In this paper, we obtain bounds for the extreme entries of the principal eigenvector of a hypergraph; these bounds are computed using the spectral radius and…”
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Complementarity spectrum of digraphs by Bravo, Diego, Cubría, Florencia, Fiori, Marcelo, Trevisan, Vilmar

“…In this paper we study the complementarity spectrum of digraphs, with special attention to the problem of digraph characterization through this complementarity…”
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Preface to the Special Issue of ILAS 2019: Linear Algebra without Borders, The 22nd ILAS Conference, Rio de Janeiro, Brazil, July 08–12, 2019 by Abreu, Nair, Helmberg, Christoph, Kutyniok, Gitta, Trevisan, Vilmar

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