The spectral extrema of graphs of odd size forbidding $H(4,3)$ beyond the book graph

Abdul Basit Wani, S. Pirzada, Amir Rehman

A graph is said to be $H$-free if it does not contain a subgraph isomorphic to $H$. The fish graph, denoted by $H(4,3)$, is a $6-$vertex graph obtained from a cycle of length $4$…