Some sufficient conditions on hamilton graphs with toughness [PDF]
Frontiers in Computational Neuroscience, 2022 Let G be a graph, and the number of components of G is denoted by c(G). Let t be a positive real number. A connected graph G is t-tough if tc(G − S) ≤ |S| for every vertex cut S of V(G). The toughness of G is the largest value of t for which G is t-tough,
Gaixiang Cai +4 more
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On Singular Signed Graphs with Nullspace Spanned by a Full Vector: Signed Nut Graphs
Discussiones Mathematicae Graph Theory, 2022 A signed graph has edge weights drawn from the set {+1, −1}, and is sign-balanced if it is equivalent to an unsigned graph under the operation of sign switching; otherwise it is sign-unbalanced.
Bašić Nino +3 more
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The Number of P-Vertices of Singular Acyclic Matrices: An Inverse Problem
Discussiones Mathematicae Graph Theory, 2020 Let A be a real symmetric matrix. If after we delete a row and a column of the same index, the nullity increases by one, we call that index a P-vertex of A.
Du Zhibin, da Fonseca Carlos M.
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On the spectral properties of real antitridiagonal Hankel matrices
Special Matrices, 2022 In this article, we express the eigenvalues of real antitridiagonal Hankel matrices as the zeros of given rational functions. We still derive eigenvectors for these structured matrices at the expense of prescribed eigenvalues.
Lita da Silva João
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A note on eigenvalues location for trace zero doubly stochastic matrices [PDF]
, 2015 Some results on the location of the eigenvalues of trace zero doubly stochastic matrices are provided. A result similar to that provided in [H. Perfect and L. Mirsky. Spectral properties of doubly–stochastic matrices.
BENVENUTI, Luca
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A recursive condition for the symmetric nonnegative inverse eigenvalue problem
Revista Integración, 2017 In this paper we present a sufficient ondition and a necessary condition for Symmetri Nonnegative Inverse Eigenvalue Problem. This condition is independent of the existing realizability criteria.
Elvis Ronald Valero +2 more
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The smallest singular value of certain Toeplitz-related parametric triangular matrices
Special Matrices, 2021 Let L be the infinite lower triangular Toeplitz matrix with first column (µ, a1, a2, ..., ap, a1, ..., ap, ...)T and let D be the infinite diagonal matrix whose entries are 1, 2, 3, . . . Let A := L + D be the sum of these two matrices.
Solary Maryam Shams +2 more
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The effect of removing a 2-downer edge or a cut 2-downer edge triangle for an eigenvalue
Special Matrices, 2023 Edges in the graph associated with a square matrix over a field may be classified as to how their removal affects the multiplicity of an identified eigenvalue.
Toyonaga Kenji
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Proof of a conjecture of Graham and Lov\'asz concerning unimodality of coefficients of the distance characteristic polynomial of a tree [PDF]
, 2017 We establish a conjecture of Graham and Lov\'asz that the (normalized) coefficients of the distance characteristic polynomial of a tree are unimodal; we also prove they are log ...
Aalipour, Ghodratollah +7 more
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Inclusion regions and bounds for the eigenvalues of matrices with a known eigenpair
Special Matrices, 2020 Let (λ, v) be a known real eigenpair of an n×n real matrix A. In this paper it is shown how to locate the other eigenvalues of A in terms of the components of v. The obtained region is a union of Gershgorin discs of the second type recently introduced by
Marsli Rachid, Hall Frank J.
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