On the least distance eigenvalue of a graph

Denote by D(G)=(di,j)n×n the distance matrix of a connected graph G with n vertices, where dij is equal to the distance between vertices vi and vj in G. The least eigenvalue of D(G) is called the least distance eigenvalue of G, denoted by λn. In this paper, we determine all the graphs with λn∈[−2.383,0].