More on signed graphs with at most three eigenvalues

Citation

Ramezani F, Rowlinson P & StaniĆ Z (2022) More on signed graphs with at most three eigenvalues. Discussiones Mathematicae Graph Theory, 42 (4), pp. 1313-1331. https://doi.org/10.7151/dmgt.2393

Abstract
We consider signed graphs with just 2 or 3 distinct eigenvalues, in particular (i) those with at least one simple eigenvalue, and (ii) those with vertexdeleted subgraphs which themselves have at most 3 distinct eigenvalues. We also construct new examples using weighing matrices and symmetric 3-class association schemes

Keywords
adjacency matrix; simple eigenvalue; strongly regular signed graph; vertex-deleted subgraph; weighing matrix; association scheme

Journal
Discussiones Mathematicae Graph Theory: Volume 42, Issue 4