Journal of the
Korean Mathematical Society JKMS

Let $R$ be a ring. A right $R$-module $M$ is called perfect if $M$ possesses a projective cover. In this paper, we consider the relationship between the class of perfect modules and other classes of modules. Some known rings are characterized by these relationships.

Keywords: projective cover, $\mathcal{C}_{P}$-hereditary ring, perfect ring, small submodule

MSC numbers: 16D10, 16L30