  Spectral radius of a graph $G$ is the largest eigenvalue of adjacency matrix
of $G$. The least eigenvalue of a graph $G$ is the least eigenvalue of
adjacency matrix of $G$. In this paper we determine the graphs which attain
respectively the minimum spectral radius and the minimum least eigenvalue among
all complements of connected simple graphs with given connectivity. Spectral
radius of a graph $G$ is the largest eigenvalue of adjacency matrix of $G$. The
least eigenvalue of a graph $G$ is the least eigenvalue of adjacency matrix of
$G$. In this paper we determine the graphs which attain respectively the
minimum spectral radius and the minimum least eigenvalue among all complements
of connected simple graphs with given connectivity.
