28 papers
Artin algebras of small representation bound
Youqi Yin, Shiping Liu
This paper introduces a novel classification approach for representation-finite artin algebras in terms of the maximal length of their indecomposable modules of finite length, whic…
Equivalence of Lin--Lu--Yau curvature and 1/2-Ollivier curvature on weighted graphs
Shiping Liu, Yunyan Yang
In this note, we prove that, on weighted graphs, the Lin--Lu--Yau curvature coincides with the -Ollivier curvature up to scaling whenever the idleness parameter . Mor…
An extremal theorem for positive curvature of graphs
Kaizhe Chen, Shiping Liu, Zhe You
We prove an extremal theorem for positive Ollivier/Lin--Lu--Yau curvature: every graph of order \(n\geq 8\) with more than \[ T(n)=\frac{n^2-3n}{2}-\left\lceil\frac{n}{2}\right\rce…
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…
Regular Lichnerowicz-sharp graphs are hypercube bundles
Yanlong Ding, Shiping Liu, Chiyu Zhou
Hypercube graphs are fundamental model spaces of positive curvature in discrete comparison geometry. Let be a finite, connected, simple, unweighted graph with Bakry--Émery curv…
On Lichnerowicz sharp distance-regular graphs
Kaizhe Chen, Shiping Liu, Heng Zhang
The first non-zero Laplacian eigenvalue of a finite graph is bounded below by its minimum Lin--Lu--Yau curvature . This is a discrete analogue of the classical Lichnerow…