8 papers
Vertex ordering characterizations of interval r-graphs
Indrajit Paul, Ashok Kumar Das
An r-partite graph is an interval r-graph if corresponding to each vertex we can assign an interval of the real line such that two vertices u and v of different partite sets are ad…
Circular-arc H-graphs: Ordering Characterizations and Forbidden Patterns
Indrajit Paul, Ashok Kumar Das
We introduce the class of circular-arc H-graphs, which generalizes circular-arc graphs, particularly circular-arc bigraphs. We investigate two types of ordering-based characterizat…
New Vertex Ordering Characterizations of Circular-Arc Bigraphs
Indrajit Paul, Ashok Kumar Das
In this article, we present two new characterizations of circular-arc bigraphs based on their vertex ordering. Also, we provide a characterization of circular-arc bigraphs in terms…
Bipartite Powers of Certain Classes of Bipartite Graphs
Indrajit Paul, Ashok Kumar Das
The concept of graph powers has been extensively studied in graph theory. Analogous to graph powers, Chandran et al. [3] introduced the notion of bipartite powers for bipartite gra…
Obstruction characterization of co-TT graphs
Ashok Kumar Das, Indrajit Paul
Threshold tolerance graphs and their complement graphs, known as co-TT graphs, were introduced by Monma, Reed, and Trotter[24]. Building on this, Hell et al.[19] introduced the con…
On powers of circular arc graphs
Ashok Kumar Das, Indrajit Paul
A class of graphs is closed under powers if for every graph and every , . Also is strongly closed u…
Signed interval graphs and bigraphs: A generalization of interval graphs and bigraphs
Ashok Kumar Das, Indrajit Paul
In this paper, we define and characterize signed interval graphs and bigraphs introducing the concept of negative interval. Also we have shown that these classes of graphs are resp…
On Hamiltonian-Connected and Mycielski graphs
Ashok Kumar Das, Indrajit Paul
A graph is Hamiltonian-connected if there exists a Hamiltonian path between any two vertices of . It is known that if is 2-connected then the graph is Hamiltonian-…