Results 31 to 40 of about 179,652 (285)
Cospectral Pairs of Regular Graphs with Different Connectivity
Discussiones Mathematicae Graph Theory, 2020 For vertex- and edge-connectivity we construct infinitely many pairs of regular graphs with the same spectrum, but with different connectivity.
Haemers Willem H.
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Graphs With All But Two Eigenvalues In [−2, 0]
Discussiones Mathematicae Graph Theory, 2020 The eigenvalues of a graph are those of its adjacency matrix. Recently, Cioabă, Haemers and Vermette characterized all graphs with all but two eigenvalues equal to −2 and 0.
Abreu Nair +4 more
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The spectral determination of the connected multicone graphs
AKCE International Journal of Graphs and Combinatorics, 2021 The main goal of the paper is to answer an unsolved problem. A multicone graph is defined to be the join of a clique and a regular graph, and a wheel as the join of a vertex and a cycle.
Ali Zeydi Abdian +4 more
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Frontiers in NeuroscienceIntroductionSubstance use disorders (SUDs) are heterogeneous diseases with overlapping biological mechanisms and often present with co-occurring disease, such as cardiovascular disease (CVD).
Everest Castaneda +3 more
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The distance spectrum of corona and cluster of two graphs
AKCE International Journal of Graphs and Combinatorics, 2015 Let G be a connected graph with a distance matrix D. The D-eigenvalues {μ1,μ2,…,…,μp} of G are the eigenvalues of D and form the distance spectrum or D-spectrum of G.
G. Indulal, Dragan Stevanović
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The coalescence of multi-wheel and starlike graphs is DLS [PDF]
Journal of Mahani Mathematical ResearchThe Laplacian spectrum of a graph is obtained by taking the difference of the adjacency spectrum from the diagonal matrix of degrees. If a graph has a unique Laplacian spectrum, it means that it can be identified by this spectrum, it is called $DLS ...
Mohammad Hasan Ahangarani Farahani +1 more
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Eigenvalue −1 of the Vertex Quadrangulation of a 4-Regular Graph
AxiomsThe vertex quadrangulation QG of a 4-regular graph G visually looks like a graph whose vertices are depicted as empty squares, and the connecting edges are attached to the corners of the squares.
Vladimir R. Rosenfeld
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Reconstruction of Weighted Graphs by their Spectrum
European Journal of Combinatorics, 2000 A weighted graph \(G\) is a pair \((A,M)\) where \(A\) and \( M\) are two matrices with \(A_{ii}=0\) and \(M\) is real diagonal. If the mass coefficients \(m_i\) are equal to 1, then \(G\) is a simple graph. If \(m_i >0\) and \(A_{ij} \geq 0\), the weighted graph is a model for a molecule or, alternatively, a discrete model of an inhomogeneous drum ...
Lorenz Halbeisen, Norbert Hungerbühler
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Some Algebraic Properties of a Class of Integral Graphs Determined by Their Spectrum
Journal of Mathematics, 2021 Let Γ=V,E be a graph. If all the eigenvalues of the adjacency matrix of the graph Γ are integers, then we say that Γ is an integral graph. A graph Γ is determined by its spectrum if every graph cospectral to it is in fact isomorphic to it. In this paper,
Jia-Bao Liu +2 more
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On the Spectrum of the Generalised Petersen Graphs [PDF]
Graphs and Combinatorics, 2016 We show that the gap between the two greatest eigenvalues of the generalised Petersen graphs $P(n,k)$ tends to zero as $n \rightarrow \infty$. Moreover, we provide explicit upper bounds on the size of this gap. It follows that these graphs have poor expansion properties for large values of $n$. We also show that a positive proportion of the eigenvalues
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