The Maximum Spectral Radius of Graphs Without Friendship Subgraphs

Source abstract

A graph on $2k+1$ vertices consisting of $k$ triangles which intersect in exactly one common vertex is called a $k-$friendship graph and denoted by $F_k$. This paper determines the graphs of order $n$ that have the maximum (adjacency) spectral radius among all graphs containing no $F_k$, for $n$ sufficiently large.