Folding trees gracefully

When a graceful labeling of a bipartite graph assigns the smaller labels to the vertices of one of the stable sets of the graph, the assignment is called an α-labeling. Any graph that admits such a labeling is an α-graph. In this work we extend the concept of vertex amalgamation to generate a new cl...

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Bibliographic Details
Main Authors: Christian Barrientos, Sarah Minion
Format: Article
Language:English
Published: Taylor & Francis Group 2020-09-01
Series:AKCE International Journal of Graphs and Combinatorics
Subjects:
Online Access:http://dx.doi.org/10.1016/j.akcej.2019.10.001
Description
Summary:When a graceful labeling of a bipartite graph assigns the smaller labels to the vertices of one of the stable sets of the graph, the assignment is called an α-labeling. Any graph that admits such a labeling is an α-graph. In this work we extend the concept of vertex amalgamation to generate a new class of α-graphs obtained by a sequence of k-vertex amalgamations of t copies of an α-tree. This procedure is also applied to any collection of α-trees such that any pair of trees in this collection have stable sets with the same cardinalities. We also use this idea on other types of α-graphs. In addition, we present a family of α-trees of even diameter formed with four caterpillars of the same size.
ISSN:0972-8600
2543-3474