6 papers
The sharp asymptotic density of zero-sum-free spherical sets
Hong-Jun Ge, Zixiang Xu
A measurable set is called zero-sum-free if there are no with $\boldsymbol{x}+\boldsymbol{y}+\bolds…
Co-edge-regular graphs with four eigenvalues and unbounded coherent rank
Edwin R. van Dam, Hong-Jun Ge, Jack H. Koolen
In the regular three-eigenvalue setting, spectral complexity and coherent-algebraic complexity coincide: a connected regular graph has exactly three distinct eigenvalues if and onl…
Wang-Qiu-Hu switching and isomorphism
Aida Abiad, Hong-Jun Ge
Cospectral graphs (graphs that share the same eigenvalues) expose the limitations of using the graph spectrum to uniquely identify graphs, and they also help to understand what str…
Kusner's conjecture: Exact values and linear bounds
Hong-Jun Ge, Zixiang Xu, Yang Zhou
In 1983, Kusner conjectured that the largest equilateral set in with metric has cardinality when and when This conjecture…
A Bose-Laskar-Hoffman theory for -bounded graphs with fixed smallest eigenvalue
Jack H. Koolen, Hong-Jun Ge, Chenhui Lv +1
In 2018, by Ramsey and Hoffman theory, Koolen, Yang, and Yang presented a structural result on graphs with smallest eigenvalue at least and large minimum degree. In this study…
On co-edge-regular graphs with 4 distinct eigenvalues
Hong-Jun Ge, Jack H. Koolen
Tan et al. conjectured that connected co-edge-regular graphs with four distinct eigenvalues and fixed smallest eigenvalue, when having sufficiently large valency, belong to two dif…