Cospectral mates for generalized Johnson and Grassmann graphs

2023/05/26 by Aida Abiad, Jozefien D’haeseleer, Abiad, Aida +5
Computer Science · Mathematics · #05C50 #15A18 #Advanced Topics in Algebra #Combinatorics (math.CO) #FOS: Mathematics #Graph theory and applications #Matrix Theory and Algorithms

paper · pdf · doi:10.48550/arxiv.2305.16858

openalex publication_date 2023/05/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We provide three infinite families of graphs in the Johnson and Grassmann schemes that are not uniquely determined by their spectrum. We do so by constructing graphs that are cospectral but non-isomorphic to these graphs.

Related

• Cospectral mates for the union of some classes in the Johnson association scheme
• Walk Matrix-Based Upper Bounds on Generalized Cospectral Mates
• Graphs with at most one generalized cospectral mate
• Cospectral pairs of regular graphs with different connectivity
• Constructing cospectral graphs via regular rational orthogonal matrix with level two and three