Minimal Estrada index of the trees without perfect matchings
نویسندگان
چکیده
منابع مشابه
Klazar trees and perfect matchings
Martin Klazar computed the total weight of ordered trees under 12 different notions of weight. The last and perhaps most interesting of these weights, w12, led to a recurrence relation and an identity for which he requested combinatorial explanations. Here we provide such explanations. To do so, we introduce the notion of a “Klazar violator” vertex in an increasing ordered tree and observe that...
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Abstract The Laplacian Estrada index of a graphG is defined as LEE(G) = ∑n i=1 e μi , where μ1 ≥ μ2 ≥ · · · ≥ μn−1 ≥ μn = 0 are the eigenvalues of its Laplacian matrix. An unsolved problem in [19] is whether Sn(3, n − 3) or Cn(n − 5) has the third maximal Laplacian Estrada index among all trees on n vertices, where Sn(3, n − 3) is the double tree formed by adding an edge between the centers of ...
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ژورنال
عنوان ژورنال: The Electronic Journal of Linear Algebra
سال: 2019
ISSN: 1081-3810
DOI: 10.13001/1081-3810.3355