Long-Tu Yuan

collaborators

5 papers

math.CO2026

Exact generalized TurÃ¡n number of vertex-disjoint paths of length two

Qi Wu, Long-Tu Yuan

We determine the generalized TurÃ¡n number of vertex-disjoint paths of length two and characterize all corresponding extremal graphs. Our proof combines the LovÃ¡sz form of the Kru…

math.CO2026

Strong counterexamples to a supersaturation question of Ma-Yuan

Wanfang Chen, Long-Tu Yuan

For a graph $F$ , let $h_{F} (n, q)$ be the minimum number of copies of $F$ in an $n$ -vertex graph with $ex (n, F) + q$ edges, where $ex (n, F)$ is the maximum number of edg…

math.CO2026

Triangles in graphs without the expansion of $4$ -cycle

Jialei Song, Qi Wu, Long-Tu Yuan

The expansion $F^{△}$ of a graph $F$ is the graph obtained from $F$ by replacing each edge with a triangle. Lv \etal proposed a conjecture on the maximum number of triangle…

math.CO2026

Anti-Ramsey numbers for cancellative configurations in p-graphs

Cheng Chi, Long-tu Yuan

We study edge-colorings of the complete $p$ -graph on $n$ vertices that contain no three edges $A, B, C$ of distinct colors such that the symmetric difference of $A$ and $B$ is contai…

math.CO2025

Exact TurÃ¡n numbers of two vertex-disjoint paths

Miao Dong, Bo Ning, Long-Tu Yuan +1

The TurÃ¡n number of a graph $H$ is the maximum number of edges in any graph of order $n$ that does not contain $H$ as a subgraph. In 1959, Erd\H os and Gallai obtained a sharp upp…

Exact generalized TurÃ¡n number of vertex-disjoint paths of length two

Strong counterexamples to a supersaturation question of Ma-Yuan

Triangles in graphs without the expansion of 4-cycle

Anti-Ramsey numbers for cancellative configurations in p-graphs

Exact TurÃ¡n numbers of two vertex-disjoint paths

Triangles in graphs without the expansion of $4$ -cycle