Ruifang Liu

collaborators

6 papers

math.CO2026

Extremal results for graphs with binding number strictly less than $1/ r$

Ruifang Liu, Hongyu Chen, Ao Fan

The binding number $b (G)$ of a graph, introduced by Woodall [J. Combin. Theory, Ser. B, 1973], is a central topic of both structural and extremal graph theory. It is closely relate…

math.CO2026

Spectral radius and rainbow $k$ -factors in a bipartite graph family

Meng Chen, Ruifang Liu

Let $G = {G_{1}, G_{2}, \dots, G_{k n}}$ be a family of balanced bipartite graphs on the same vertex set $[2 n]$ . A rainbow $k$ -factor of $G$ is defined as a $k$ -fa…

math.CO2026

Spectral radius and rainbow Hamiltonicity in bipartite graphs

Meng chen, Ruifang Liu, Qixuan Yuan

Let $G = {G_{1}, G_{2}, \dots, G_{k}}$ be a family of bipartite graphs on the same vertex set. A rainbow Hamilton path (cycle) in $G$ is a path (cycle) that visits…

math.CO2026

Spectral radius and parity $[a, b]$ -factors in graphs

Ruifang Liu, Ting Xu, Suil O

Let $a$ , $b$ , and $n$ be three integers such that $1 \leq a \leq b < n$ , $a \equiv b$ (mod $2$ ), and $na$ is even. A parity $[a, b]$ -factor of $G$ is a spanning subgraph $H$ such tha…

math.CO2025

Toughness in regular graphs from eigenvalues

Ruifang Liu, Ao Fan, Jinlong Shu

The {\it toughness} $Ï(G)=\mathrm{min}\{\frac{|S|}{c(G-S)}: S~\mbox{is a vertex cut in}~G\}$ for $G ≆ K_{n},$ which was initially proposed by ChvÃ¡tal in 1973. A graph $G$ is ca…

math.CO2025

TurÃ¡n number of books in non-bipartite graphs

Lu Miao, Ruifang Liu, Edwin R. van Dam

Let $ex (n, H)$ be the TurÃ¡n number of $H$ for a given graph $H$ . A graph is color-critical if it contains an edge whose removal reduces its chromatic number. Simonovits'…

Extremal results for graphs with binding number strictly less than 1/r

Spectral radius and rainbow k-factors in a bipartite graph family

Spectral radius and rainbow Hamiltonicity in bipartite graphs

Spectral radius and parity [a,b]-factors in graphs

Toughness in regular graphs from eigenvalues

TurÃ¡n number of books in non-bipartite graphs

Extremal results for graphs with binding number strictly less than $1/ r$

Spectral radius and rainbow $k$ -factors in a bipartite graph family

Spectral radius and parity $[a, b]$ -factors in graphs