Lihua Feng

activity

20242026

collaborators

8 papers

math.CO2026

Bollobás-type inequalities for subspaces via weight invariance

Zhiyi Liu, Lihua Feng, Tingzeng Wu

Let $V$ be an $n$ -dimension real vector space with a direct sum decomposition $V = V_{1} \oplus \dots \oplus V_{r}$ . Let $P = {(A_{i}, B_{i}) : i \in [m]}$ be a skew Bollobás…

math.CO2026

Subspace variations of the weighted skew Bollobás theorem

Yongjiang Wu, Yongtao Li, Lu Lu +1

Let $V$ be a finite-dimensional real vector space. A collection $P = {(A_{i}, B_{i})}_{i = 1}^{m}$ of pairs of subspaces of $V$ is called a skew Bollobás system if $\dim(A_i\cap…

math.CO2025

The number of rooted spanning forests of bicirculant graphs

Jing Yang, Lihua Feng, Rongrong Lu +1

A bi-Cayley graph over the cyclic group $(Z_{n}, +)$ is called a bicirculant graph. Let $Γ = B C (Z_{n}; R, T, S)$ be a bicirculant graph with $R=-R\subseteq \mathbb{Z}_n\s…

math.CO2025

Two results on set families: sturdiness and intersection

Yongjiang Wu, Zhiyi Liu, Lihua Feng +1

This paper resolves two open problems in extremal set theory. For a family $F \subseteq 2^{[n]}$ and $i, j \in [n]$ , we denote $\mathcal{F} (i,\bar{j})=\{F\backslash\{i\}:…

math.CO2025

Spectral extremal problems for non-bipartite graphs without odd cycles

Lantao Zou, Lihua Feng, Yongtao Li

A well-known result of Mantel asserts that every $n$ -vertex triangle-free graph $G$ has at most $⌊ n^{2} /4 ⌋$ edges. Moreover, Erdős proved that if $G$ is further non-bip…

math.CO2024

A result for hemi-bundled cross-intersecting families

Yongjiang Wu, Lihua Feng, Yongtao Li

Two families $F$ and $G$ are called cross-intersecting if for every $F \in F$ and $G \in G$ , the intersection $F \cap G$ is non-empty. It is si…