Sida Li

collaborators

3 papers

math.CO2026

A note on matchings and co-matchings in bipartite graphs

Sida Li

A class of bipartite graphs is said to have the strong ErdÅs-Hajnal property if there exists $ε > 0$ such that every graph $((A, B), E)$ in the class contains a complete…

math.CO2026

On graphs with large third eigenvalue

Giacomo Leonida, Sida Li

Given a graph $G$ , let $I^»_{3}$ denote the third largest eigenvalue of its adjacency matrix. In this paper, we prove various results towards the conjecture that $Î»_3(G) \le \frac{|V…

math.CO2025

Strengthened upper bound on the third eigenvalue of graphs

Sida Li

Let $G$ be a graph on $n \geq 3$ vertices, whose adjacency matrix has eigenvalues $I^»_{1} \geq I^»_{2} \geq \dots \geq I^»_{n}$ . The problem of bounding $I^»_{k}$ in terms of $n$ was first propos…