Ping Li

collaborators

4 papers

math.DG2025

Hamiltonian circle action, invariant hypersurface and the complex projective space

Ping Li

Let $M$ be a $2 n$ -dimensional closed symplectic manifold admitting a Hamiltonian circle action with isolated fixed points. We show that if $M$ contains an $S^{1}$ -invariant symplecti…

math.CO2025

Planar Turán numbers of three configurations

Xuqing Bai, Zhipeng Gao, Ping Li

The planar Tuán number of $H$ , denoted by $e x_{P} (n, H)$ , is defined as the maximum number of edges in an $n$ -vertex $H$ -free planar graph. The exact value of $ex_{\mathca…

math.CO2025

Dense $2$ -connected planar graphs and the planar Turán number of $2 C_{k}$

Ping Li

Shi, Walsh and Yu demonstrated that any dense planar graph with certain property (known as circuit graph) contains a large near-triangulation. We extend the result to $2$ -connected…

math.DG2025

Chern numbers on positive vector bundles and combinatorics

Ping Li

Combinatorial ideas are developed in this article to study Chern numbers on ample and numerically effective vector bundles. An effective lower bound for Chern numbers of ample vect…

Hamiltonian circle action, invariant hypersurface and the complex projective space

Planar Turán numbers of three configurations

Dense 2-connected planar graphs and the planar Turán number of 2Ck​

Chern numbers on positive vector bundles and combinatorics

Dense $2$ -connected planar graphs and the planar Turán number of $2 C_{k}$