10 papers
A complete solution to the Boots-Royle/Cao-Vince conjecture
Lele Liu, Bo Ning, Yi Wang
Boots and Royle, and independently Cao and Vince, conjectured that the join of an edge and a path on vertices is the unique planar graph of maximum adjacency spectral radius…
The largest Laplacian eigenvalue of induced--free graphs
Lele Liu, Bo Ning
Let be a simple graph of maximum degree , and let denote the largest eigenvalue of its Laplacian matrix. For a fixed integer , Aharoni, Alon, and Berger (20…
An exponentially small gap of the Perron vector on independent sets
Hongzhang Chen, Jianxi Li, Yongtao Li +2
A classical result of CioabÄ states that if is a connected graph with the unit Perron vector , then any independent set of satisfies $\sum_{v\in S} x_v^2 \…
A short proof of a perturbation inequality for the spectral radius
Lele Liu, Bo Ning
Let be a simple graph, and denote by its spectral radius. Sun and Das (2020) established that for any non-isolated vertex with degree , \[ λ(G)\leq \sqrt{λ(…
An Improved Interpolation Theorem and Disproofs of Two Conjectures on 2-Connected Subgraphs
Haiyang Liu, Bo Ning
We prove that any \(2\)-connected graph \(G\) on \(n\) vertices with minimum degree \(δ(G) \ge \frac{n}{4}+2\) contains a \(2\)-connected subgraph of order \(k\) for every integer…
A new spectral Turán theorem for weighted graphs and consequences
Lele Liu, Bo Ning
Confirming a conjecture of Elphick and Edwards and strengthening a spectral theorem of Wilf, Nikiforov proved that for any -free graph , , w…