A characterization on trees $T$ with $m(T,\lambda )=p(T)-2$

Sarula Chang, Jianxi Li, Yirong Zheng

Let $m(G,\lambda )$ be the multiplicity of an eigenvalue $\lambda$ of a connected graph $G$. Wang et al. [Linear Algebra Appl. 584(2020), 257-266] proved that for any connected graph $G\neq C_n…