Jian Zheng

collaborators

3 papers

math.CO2025

Some Turán-type results for the signless Laplacian spectral radius

Jian Zheng, Yongtao Li, Yi-Zheng Fan

Half a century ago, Bollobás and Erdős [Bull. London Math. Soc. 5 (1973)] proved that every $n$ -vertex graph $G$ with $e (G) \geq (1 - \frac{1}{k} + ε) \frac{n ^{2}}{2}$ edges c…

math.CO2025

The signless Laplacian spectral Turán problems for color-critical graphs

Jian Zheng, Yongtao Li, Honghai Li

The well-known Turán theorem states that if $G$ is an $n$ -vertex $K_{r + 1}$ -free graph, then $e (G) \leq e (T_{n, r})$ , with equality if and only if $G$ is the $r$ -partite Turán graph $T…

math.CO2025

A signless Laplacian spectral Erdös-Stone-Simonovits theorem

Jian Zheng, Honghai Li, Li Su

The celebrated Erdős--Stone--Simonovits theorem states that $ex (n, F) = (1 - \frac{1}{χ ( F ) - 1} + o (1)) \frac{n ^{2}}{2}$ , where $χ (F)$ is the chromatic number of $F$ . In 2…