In this paper, we introduce a class of graphs that generalize threshold graphs by introducing threshold tolerances. Several characterizations of these graphs are presented, one of which leads to a polynomial-time recognition algorithm. It is also shown that the complements of these graphs contain in
Box-threshold graphs
โ Scribed by Uri N. Peled; Bruno Simeone
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- English
- Weight
- 608 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
โฆ Synopsis
A graph is called box-threshold when all pairs of vertices with incomparable neighborhoods have the same degree. Several properties of box-threshold graphs, generalizing properties of threshold graphs, are proved. A transportation model with priority constraints is used to characterize their degree sequences. Further characterizations are given using the concept of the frame of a graph.
1. Introduction
We consider finite undirected loopless graphs without multiple edges, except that loops will be used in Section 4. For graph G(V,E), the vicinal preorder 3 on V is defined by
That is, x a y if and only if every neighbor of y is a neighbor of x or x itself.
Graph G is a threshold graph when its vicinal preorder is a total (linear)
order. This means that there do not exist incomparable vertices, i.e.,
๐ SIMILAR VOLUMES
After the graph structures of self-dual nonsingular (i.e. one-to-one) transformations of (0, 1)" are described, a construction method of generating minimal nonsingular threshold transformations from lower-dimensional ones is presented. Theorems which concern nonsingular threshold transformations and