Extremal graphs with respect to the vertex PI index
نویسندگان
چکیده
منابع مشابه
Some Graphs with Extremal Pi Index
The Padmakar-Ivan (PI) index is a Wiener-Szeged-like topological index, which reflects certain structural features of organic molecules. In this paper, we study the maximum PI indices and the minimum PI indices for trees and unicyclic graphs respectively.
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The Padmakar–Ivan (PI) index of a graph G is defined as the sum of terms [mu(e) + mv(e)] over all edges of G, where e is an edge, connecting the vertices u and v, wheremu(e) is the number of edges of G lying closer to the vertex u than to the vertex v, and where mv(e) is defined analogously. The extremal values of the PI index are determined in the class of connected bipartite graphs with a giv...
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ژورنال
عنوان ژورنال: Applied Mathematics Letters
سال: 2009
ISSN: 0893-9659
DOI: 10.1016/j.aml.2009.07.005