Sudev Naduvath, Germina K. Augusthy, Johan Kok

Copyright: © 2020
|Pages: 43

DOI: 10.4018/978-1-5225-9380-5.ch009

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TopIn graph theory, graph labelling is an assignment of labels to the vertices and/or edges of a graph with respect to certain restrictions and in accordance with certain predefined rules. For the past few decades, graph labelling has become a fruitful research area in graph theory. Different graph labellings have resulted from practical considerations. They are not only of theoretical interests but have many practical implications also. For many applications, the edges or vertices of a given graph are given labels that are meaningful in the context.

Valuation of a graph is a one to one mapping of the vertex set of on to the set of all integers . Graph labeling has become a fertile research area in graph theory after the introduction of the notion of certain types number valuations, called -valuations, of graphs in Rosa (1967). The most popular one among the number valuations of graphs is *-valuation* or *graceful labelling* of a graph (see Golomb, 1972; Rosa, 1967) which is defined as an injective function

Motivated by various problems in social networks, a set analogue of number valuations called set-valuation of graphs, has been introduced in Acharya (1983). In the number valuations, the elements of a graph are assigned to numbers while in the set-valuations, the elements of a graph are assigned to sets subject to certain conditions. The mathematical definition of a set-valuation of a graph concerned is as given below (see Acharya, 1983):

For a graph and a non-empty set , a *set-labeling* or a set-valuation of , with respect to the set , is an injective set-valued function

Many significant and interesting studies on set-labelling of graphs have been done in the last two decades (see [1-10, 32, 33, 91]).

Sequential Sumset Labeling: A sumset labeling with the collection of all vertex set-set-labels and edge-set-labels together with the nullset form the powerset of the ground set.

Weak Sumset Labeling: A sumset labeling in which the set-indexing number of each edge is equal to that of at least one of its end vertices.

Set-Indexing Number of an Element: The cardinality of the set-label of that element.

Set-Label Hypergraphs: The hypergraphs whose elements are the set-labels of the elements of a sumset graph.

Strong Sumset Labeling: A sumset labeling in which the set-indexing number of every edge is the product of the set-indexing numbers of its end vertices.

Sumset Signed Graph: A signed graph with a sumset labeling and whose signs are induced by the set-labels of its elements.

Graceful Sumset Labeling: A sumset labeling with the collection of all edge set-set-labels together with the null set and {0} form the power set of the ground set.

Sumset Labeling: An assignment of number sets to the elements of a graph such that the set-label of each edge is the sumset of the set-labels of its end vertices.

Arithmetic Sumset Labeling: A sumset labeling in which the set-labels of all vertices and edges of the graph are arithmetic progressions.

Topogenic Sumset Labeling: A sumset labeling with the collection of all vertex set-set-labels and edge-set-labels together with the nullset form a topology of the ground set.

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