3 papers
math.CO2026
Bounds on median eigenvalues of graphs of bounded degree
Hricha Acharya, Zilin Jiang, Shengtong Zhang
We prove that for every integer , the median eigenvalues of any graph of maximum degree are bounded above by . We also prove that, in three separate cases,…
math.CO2025
Beyond the classification theorem of Cameron, Goethals, Seidel, and Shult
Hricha Acharya, Zilin Jiang
In 1976, Cameron, Goethals, Seidel, and Shult classified all the graphs whose smallest eigenvalue is at least by relating such graphs to root systems that appear in the classi…
math.CO2025
Median eigenvalues of subcubic graphs
Hricha Acharya, Benjamin Jeter, Zilin Jiang
We show that the median eigenvalues of every connected graph of maximum degree at most three, except for the Heawood graph, are at most in absolute value, resolving open proble…