International Journal of Mathematics and Mathematical Sciences
We provide characterization of symmetric integer matrices for rank at most 2 that have integer spectrum and give some constructions for such matrices of rank 3. We also make some connection between Hanlon’s conjecture and integer eigenvalue problem.
Cao, Lei and Koyuncu, Selcuk, "Symmetric Integer Matrices Having Integer Eigenvalues" (2016). Mathematics Faculty Articles. 269.