activity
20202026
most citedSpectral extremal graphs for the bowtie

29 citations · 32 across the 6 of their papers we have counts for

collaborators

6 papers

math.CO2026

On the sum of the two largest eigenvalues of the curl-curl operator on graphs

Yueli Han, Lu Lu, Jianfeng Wang

The Grone--Merris conjecture, proved by Bai in~2011, states that the spectrum of the graph Laplacian is majorized by the conjugate of…

math.CO2026

Helmholzian Spectra of Graphs: Novel Properties

Lu Lu, Yongtang Shi, Zoran Stanić +2

Let $\grad$, $\curl$, and $\dv$ be the graph-theoretic analogues of the gradient, curl, and divergence operators from multivariate calculus. The graph Laplacian $-\dv \grad$ gives…

math.CO2026

Helmholzian spectra of graphs: basic properties

Lu Lu, Yongtang Shi, Zoran Stanić +2

The Helmholtzian matrix of a graph is a graph-theoretic analogue of the vector Laplacian (or Helmholtz operator) [S. Li, L. Lu, J.F. Wang, A graph discretization of…

math.CO2022★ 29 cited

Spectral extremal graphs for the bowtie

Yongtao Li, Lu Lu, Yuejian Peng

Let be the (friendship) graph obtained from triangles by sharing a common vertex. The -free graphs of order which attain the maximal spectral radius was firstly…

math.CO2022

Spectral radius of graphs forbidden or

Junying Lu, Lu Lu, Yongtao Li

Let be the graph obtained from a cycle by adding a new vertex connecting two adjacent vertices in . In this note, we obtain the graph maximizing th…

math.CO2020★ 3 cited

On the largest and least eigenvalues of eccentricity matrix of trees

Xiaocong He

The eccentricity matrix of a graph is constructed from the distance matrix of by keeping only the largest distances for each row and each column. This matr…