Questions tagged [cograph]
The cograph tag has no usage guidance.
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Upperbound the order of P3-free partition of P4-free graphs
A graph $G$ is $P_k$-free if and only if $G$ does not have an induced subgraph isomorphic to a path of $k$ vertices. Thus, $P_2$-free graphs are exactly independent sets (or stable sets). $P_4$-free ...
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On the size of P4-transversals of graphs
A subset $T$ of vertices of a graph $G$ is called a $P_4$-transversal if $T$ intersects every $P_4$ of $G$. In the context of this question, we consider $P_4$ as an induced path on 4 vertices.
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Chromatic number of G+v where G is a cograph
Cograph is a well-know graph that does not have induced $P_4$. My questions are about determining the chromatic number of graphs in the class cograph+v.
Notations:
Denote by $\chi(G)$ the chromatic ...