20.500.12556/RUL-176452 Hermitian adjacency matrices with at most three distinct eigenvalues We study oriented graphs whose Hermitian adjacency matrices of the second kind have few eigenvalues. We give a complete characterization of the oriented graphs with two distinct eigenvalues, showing that there are only four such graphs. We extend this result to mixed graphs. We show that there are infinitely many regular tournaments with three distinct eigenvalues. We extend our main results to Hermitian adjacency matrices defined over other roots of unity. Hermitian adjacency matrix few distinct eigenvalues oriented graphs mixed graphs true false true Angleški jezik Angleški jezik Članek v reviji 2025-12-01 12:29:44 2025-12-01 12:29:45 2025-12-21 04:07:25 0000-00-00 00:00:00 2026 0 0 11 str. iss. 3, art. no. 114872 Vol. 349 Mar. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2026-03-01 519.17:512 0012-365X 10.1016/j.disc.2025.114872 259134723 1-s2.0-S0012365X25004807-main.pdf 1-s2.0-S0012365X25004807-main.pdf 1 F8A819A4F44B35938F31D64DF3E1CDE7 e7207adcad5c1bcef6d834802ec54d8ac0c3a336766b043539f4f07b0715f7e7 f331e5aa-cea8-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=222786 https://www.sciencedirect.com/science/article/pii/S0012365X25004807 1 a8ed23c0-cea8-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=222785 Fakulteta za matematiko in fiziko 0 0 0