Title
Critical graphs with respect to total domination and connected domination.
Abstract
A graph G is said to be k-gamma t-critical if the total domination number gamma t(G) = k and gamma t(G + uv) < k for every uv E(G). A k-gamma c-critical graph G is a graph with the connected domination number gamma c - k and gamma c (G + uv) < k for every uv E(G). Further, a k-tvc graph is a graph with gamma t(G) - k and gamma t(G - v) < k for all v E V(G), where v is not a support vertex (i.e. all neighbors of v have degree greater than one). A 2 -connected graph G is said to be k-cvc if gamma c(G) = k and gamma c(G - v) < k for all v E V(G). In this paper, we prove that connected k-gamma t-critical graphs and k-gamma c-critical graphs are the same if and only if 3 <= k <= 4. For k >= 5, we concentrate on the class of connected k -gamma t -critical graphs G with gamma c(G) = k and the class of k - gamma c-critical graphs G with gamma(G) = k. We show that these classes intersect but they do not need to be the same. Further, we prove that 2 -connected k-tvc graphs and k-tvc graphs are the same if and only if 3 <= k <= 4. Similarly, for k >= 5, we focus on the class of 2 -connected k-tvc graphs G with N(G) = k and the class of 2 -connected k-cvc graphs G with gamma t(G) = k. We finish this paper by showing that these classes do not need to be the same.
Year
Venue
Field
2016
AUSTRALASIAN JOURNAL OF COMBINATORICS
Connected domination,Graph,Combinatorics,Mathematics
DocType
Volume
ISSN
Journal
65
2202-3518
Citations 
PageRank 
References 
0
0.34
0
Authors
3
Name
Order
Citations
PageRank
P. Kaemawichanurat100.34
Lou Caccetta2193.38
Nawarat Ananchuen3367.22