Bulletin: Classe des sciences mathématiques et natturalles - Sciences mathématiques 2005, vol. 131, br. 30, str. 93-99
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On the spectral radius of bicyclic graphs
(naslov ne postoji na srpskom)
aUniverzitet u Kragujevcu, Prirodno-matematički fakultet bYancheng Teachers College - Department of Mathematics, Yancheng, Jiangsu, P. R. China
Sažetak(ne postoji na srpskom) Let K3 and K'3 be two complete graphs of order 3 with disjoint vertex sets Let be the 5-vertex graph, obtained by identifying a vertex of K3 with a vertex of K'3. Let be the 4-vertex graph, obtained by identifying two vertices of K3 each with a vertex of K'3. Let be graph of order n, obtained by attaching k paths of almost equal length to the vertex of degree 4 of . Let be the graph of order n obtained by attaching k paths of almost equal length to a vertex of degree 3 of . Let be the set of all connected bicyclic graphs of order n, possessing k pendent vertices. One of the authors recently proved that among the elements of , either or have the greatest spectral radius. We now show that for k ≥ 1 and n ≥ k + 5, among the elements of , the graph has the greatest spectral radius.
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