Hongyang Wang

collaborators

4 papers

math.CO2026

Partition-selected flow polynomials and associated arrangements

Beifang Chen, Ying Cao, Houshan Fu +1

We introduce a partition-selection method to generalize the flow, chromatic, and Tutte polynomials of a graph by restricting the standard edge subgraph expansions to subgraphs give…

math.CO2026

Colouring ( $P_{2} \cup P_{4}$ , diamond)-free graphs with $ω$ colours

Hongyang Wang

In this paper, we establish an optimal $χ$ -binding function for $(P_{2} \cup P_{4}, diamond)$ -free graphs. We prove that for any graph $G$ in this class, $χ (G) \leq 4$ when $ω(G)=2…

math.CO2025

Optimal chromatic bound for ( $P_{2} \cup P_{4}$ , HVN)-free graphs

Lizhong Chen, Hongyang Wang

The HVN is a graph formed by removing two edges incident to the same vertex from the complete graph $K_{5}$ . In this paper, we prove that every ( $P_{2} \cup P_{4}$ , HVN)-free graph $G$ sa…

math.CO2025

Perfect divisions in ( $P_{2} \cup P_{4}$ , bull)-free graphs

Lizhong Chen, Hongyang Wang

A graph $G$ has a perfect division if its vertex set can be partitioned into two sets $A$ , $B$ such that $G [A]$ is perfect and $I ¨ (G [B]) < I ¨ (G)$ . We call $G$ perfectly divisible i…

Partition-selected flow polynomials and associated arrangements

Colouring (P2​∪P4​, diamond)-free graphs with ω colours

Optimal chromatic bound for (P2​∪P4​, HVN)-free graphs

Perfect divisions in (P2​∪P4​, bull)-free graphs

Colouring ( $P_{2} \cup P_{4}$ , diamond)-free graphs with $ω$ colours

Optimal chromatic bound for ( $P_{2} \cup P_{4}$ , HVN)-free graphs

Perfect divisions in ( $P_{2} \cup P_{4}$ , bull)-free graphs