14 papers
Supersaturation in Nosal graphs: Triangles and books
Hongzhang Chen, Yongtao Li, Quanyu Tang
In this paper, we use the spectral surplus to measure how far lies above the Nosal threshold, and prove the following edge-spectral supersaturation results f…
An edge-spectral supersaturation of Mubayi's theorem for color-critical graphs
Hongzhang Chen, Yongtao Li
We study the supersaturation problem in its edge-spectral form. Let be the adjacency spectral radius of . Nikiforov proved that every -free graph with e…
Spectral Sidorenko inequalities and edge-spectral supersaturation
Yongtao Li, Wilson Lin, Hong Liu +1
We develop a spectral approach to Sidorenko-type inequalities and apply it to establish sharp edge-spectral supersaturation results. Let be a bipartite graph with vertices…
On a conjecture of distance spectral extremal problems
Hongzhang Chen, Jianxi Li, Yongtao Li
Brualdi and Hoffman proposed a well-known problem of determining the graph with maximum adjacency spectral radius among all graphs with given size . Early work by Friedland and…
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 \…
Some Turán-type results for the signless Laplacian spectral radius
Jian Zheng, Yongtao Li, Yi-Zheng Fan
Half a century ago, Bollobás and ErdÅs [Bull. London Math. Soc. 5 (1973)] proved that every -vertex graph with edges…