On the spectral radius of block graphs having all their blocks of the same size.

Let B (n , q) be the class of block graphs on n vertices having all their blocks of the same size. We prove that if G ∈ B (n , q) has at most three pairwise adjacent cut vertices then the minimum spectral radius ρ (G) is attained at a unique graph. In addition, we present a lower bound for ρ (G) when G ∈ B (n , q). [ABSTRACT FROM AUTHOR]