collaborators

12 papers

math.CO2026

Edge-spectral supersaturation for tripartite color-critical graphs

Longfei Fang, Huiqiu Lin, Mingqing Zhai

We study edge-spectral supersaturation for two families of color-critical graphs with chromatic number three. For an integer , we define the spectral threshold \[ g_r(m):=…

math.CO2026

Spectral extremal graphs on closed surfaces of fixed Euler genus

Mingqing Zhai, Longfei Fang, Huiqiu Lin

Graph theory on surfaces extends classical graph structures to topological surfaces, providing a theoretical foundation for characterizing the embedding properties of complex netwo…

math.CO2026

On the Turán number of odd-ballooning of -chromatic graphs

Longfei Fang, Xueyi Huang, Huiqiu Lin +1

Given a graph , the Turán number is the maximum number of edges in any -vertex -free graph. The odd-ballooning of , denoted by , is a graph obta…

math.SP2026

Minimally -edge-connected graphs via spectral radius

Yu Wang, Dan Li, Huiqiu Lin

For , the -edge-connectivity of a connected graph is defined as the minimum number of edges whose removal leaves a graph with at least components. A gr…

math.CO2026

Spectral extremal results for triangle-free graphs with chromatic number at least four

Yinfen Zhu, Huiqiu Lin

A graph is called -free if it does not contain a copy of . Let denote a -free graph of order with chromatic number at least that maximizes the spect…

math.CO2026

Spectral radius, toughness and -factor of graphs

Yuanyuan Chen, Huiqiu Lin, Shucheng Li

A -regular spanning subgraph of is called a -factor. Fan, Lin and Lu [European J. Combin. 110 (2023) 103701] presented a tight sufficient condition in terms of the spectr…