9 papers
New bounds for equiangular lines and Balla's conjecture
Chuanyuan Ge, Shiping Liu
Let denote the maximum number of equiangular lines in with common angle . Balla conjectured that, if the spectral radius order $κ_{\frac{1-α}{2α…
A new proof of the Lemmens-Seidel conjecture
Chuanyuan Ge, Shiping Liu
In this paper, we give a new proof of the Lemmens-Seidel conjecture on the maximum number of equiangular lines with a common angle . This conjecture was previously re…
On finiteness of spectral radius order
Yanlong Ding, Chuanyuan Ge, Shiping Liu
The concept of spectral radius order plays an crucial role in the breakthrough work on equiangular lines due to Jiang, Tidor, Yao, Zhang, and Zhao [Ann. of Math. (2) 194 (2021), no…
Equiangular lines via nodal domains
Chuanyuan Ge, Shiping Liu
For given and , we show that the maximum multiplicity that can appear as the second largest eigenvalue of a connected graph with maximum degree at most $Δ…
Computing the -Laplacian eigenpairs of signed graphs
Chuanyuan Ge, Ouyuan Qin
As a nonlinear extension of the graph Laplacian, the graph -Laplacian has various applications in many fields. Due to the nonlinearity, it is very difficult to compute the eigen…
Spectral bounds of multi-way Cheeger constants via cyclomatic number
Chuanyuan Ge
As a non-trivial extension of the celebrated Cheeger inequality, the higher-order Cheeger inequalities for graphs due to Lee, Oveis Gharan and Trevisan provide for each an uppe…
New graph invariants based on -Laplacian eigenvalues
Chuanyuan Ge, Shiping Liu, Dong Zhang
We present monotonicity inequalities for certain functions involving eigenvalues of -Laplacians on signed graphs with respect to . Inspired by such monotonicity, we propose n…
Nodal domain theorems for -Laplacians on signed graphs
Chuanyuan Ge, Shiping Liu, Dong Zhang
We establish various nodal domain theorems for -Laplacians on signed graphs, which unify most of the existing results on nodal domains of graph -Laplacians and arbitrary symm…
Symmetric Matrices, Signed Graphs, and Nodal Domain Theorems
Chuanyuan Ge, Shiping Liu
In 2001, Davies, Gladwell, Leydold, and Stadler proved discrete nodal domain theorems for eigenfunctions of generalized Laplacians, i.e., symmetric matrices with non-positive off-d…