2 papers
math.CO2025
The Hoffman program for mixed graphs
Yuantian Yu, Edwin R. van Dam
We consider Hoffman's program about the limit points of the spectral radius of the Hermitian adjacency matrix of mixed graphs. In particular, we determine all mixed graphs without…
math.CO2024
Symmetry in complex unit gain graphs and their spectra
Pepijn Wissing, Edwin R. van Dam
Complex unit gain graphs may exhibit various kinds of symmetry. In this work, we explore structural symmetry, spectral symmetry and sign-symmetry in such graphs, and their respecti…