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Showing papers by "Steve Kirkland published in 1997"


Journal ArticleDOI
TL;DR: This work investigates how the algebraic connectivity of a weighted tree behaves when the tree is perturbed by removing one of its branches and replacing it with another, and produces a lower bound on the algebraIC connectivity of any unweighted graph in terms of the diameter and the number of vertices.
Abstract: We investigate how the algebraic connectivity of a weighted tree behaves when the tree is perturbed by removing one of its branches and replacing it with another. This leads to a number of results, for example the facts that replacing a branch in an unweighted tree by a star on the same number of vertices will not decrease the algebraic connectivity, while replacing a certain branch by a path on the same number of vertices will not increase the algebraic connectivity. We also discuss how the arrangement of the weights on the edges of a tree affects the algebraic connectivity, and we produce a lower bound on the algebraic connectivity of any unweighted graph in terms of the diameter and the number of vertices. Throughout, our techniques exploit a connection between the algebraic connectivity of a weighted tree and certain positive matrices associated with the tree.

58 citations


Journal ArticleDOI
TL;DR: In this paper, for a primitive generalized tournament matrix, upper and lower bounds on an entry in its perron vector in terms of the corresponding row sum of the matrix are presented.

14 citations


Journal ArticleDOI
TL;DR: In this paper, the general form of the characteristic polynomial of a primitive stochastic matrix of order n ⩾ 7 and exponent at least 2⌊ (n − 4) 4 ⌋ complex eigenvalues of modulus at greater than { 1 2 sin [ π(n − 1) ]} 2 (n−1) ]−2 (n-1) (observed that this last quantity tends to 1 as n → ∞).

11 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that the ranking schemes of Kendall and Wei and of Ramanujacharyula agree with the ranking generated by the row sums of the tournament matrix T.

9 citations


Journal ArticleDOI
TL;DR: For a primitive matrix A of order n + k having a primitive submatrix of order 71, the exponent of A is at most (n - 1) + 2k + 1.

1 citations