Yuejian Peng

activity

20242026

most citedSpectral supersaturation: Triangles and bowties

5 citations · 14 across the 10 of their papers we have counts for

collaborators

10 papers

math.CO2026

Saturation numbers of some joins of graphs

Xinying Hua, Yuejian Peng

Let $H$ be a graph. A graph $G$ is $H$ -saturated if $G$ is $H$ -free, but adding any edge between two non-adjacent vertices of $G$ yields an $H$ -copy as a subgraph. The saturation n…

math.CO2026

Saturation numbers for joins with graphs containing isolated vertices

Xinying Hua, Yuejian Peng

A graph $G$ is $H$ -saturated if $G$ contains no $H$ -copy as a subgraph, but adding any edge between two non-adjacent vertices in $G$ creates a copy of $H$ . The saturation number $\…

math.CO2025

A note on degree conditions for Ramsey goodness of trees

Zhidan Luo, Yuejian Peng

For given graphs $G_{1}, G_{2}$ and $G$ , let $G \to (G_{1}, G_{2})$ denote that each red-blue-coloring of $E (G)$ yields a red copy of $G_{1}$ or a blue copy of $G_{2}$ . Arag…

math.CO2025

Spectral extremal graphs for $F_{6}$ -free graphs with even size

Loujun Yu, Yuejian Peng

Let $F_{l}$ be the fan graph obtained by joining a vertex with a path on $l - 1$ vertices. Yu, Li and Peng [Discrete Math. 346 (2023)] conjectured that if the number of edges of $G$ is…

math.CO2025

Strong spectral stabilities for $C_{2 k + 1}$ -free graphs

Lantao Zou, Yongtao Li, Yuejian Peng

A stability result due to Ren, Wang, Wang and Yang [SIAM J. Discrete Math. 38 (2024)] shows that if $3 \leq r \leq 2 k$ and $n \geq 318 (r - 2)^{2} k$ , and $G$ is a $C_{2 k + 1}$ -free graph on $…

math.CO2024

A spectral Lovász-Simonovits theorem

Yongtao Li, Lihua Feng, Yuejian Peng

A fundamental result in extremal graph theory is attributed to Mantel's theorem, which states that every graph on $n$ vertices with more than $⌊ n^{2} /4 ⌋$ edges must con…

math.CO2024★ 5 cited

Spectral supersaturation: Triangles and bowties

Yongtao Li, Lihua Feng, Yuejian Peng

Recently, Ning and Zhai (2023) proved that every $n$ -vertex graph $G$ with $λ (G) \geq ⌊ n^{2} /4 ⌋$ has at least $⌊ n /2 ⌋ - 1$ triangles, unless $G=K_{\lcei…

math.CO2024★ 4 cited

A spectral Erdős-Rademacher theorem

Yongtao Li, Lu Lu, Yuejian Peng

A classical result of Erdős and Rademacher (1955) indicates a supersaturation phenomenon. It says that if $G$ is a graph on $n$ vertices with at least $\lfloor {n^2}/{4} \rfloor +1…

math.CO2024★ 5 cited

A spectral Erdős-Faudree-Rousseau theorem

Yongtao Li, Lihua Feng, Yuejian Peng

A well-known theorem of Mantel states that every $n$ -vertex graph with more than $⌊ n^{2} /4 ⌋$ edges contains a triangle. An interesting problem in extremal graph theory…

math.CO2024

Spectral extremal graphs for fan graphs

Loujun Yu, Yongtao Li, Yuejian Peng

A well-known result of Nosal states that a graph $G$ with $m$ edges and $λ (G) > m$ contains a triangle. Nikiforov [Combin. Probab. Comput. 11 (2002)] extended this result to…

Saturation numbers of some joins of graphs

Saturation numbers for joins with graphs containing isolated vertices

A note on degree conditions for Ramsey goodness of trees

Spectral extremal graphs for F6​-free graphs with even size

Strong spectral stabilities for C2k+1​-free graphs

A spectral Lovász-Simonovits theorem

Spectral supersaturation: Triangles and bowties

A spectral Erdős-Rademacher theorem

A spectral Erdős-Faudree-Rousseau theorem

Spectral extremal graphs for fan graphs

Spectral extremal graphs for $F_{6}$ -free graphs with even size

Strong spectral stabilities for $C_{2 k + 1}$ -free graphs