| Abstract: | Let $R$ be a ring, and let $(\mathcal{F}, C)$ be a cotorsion theory. In this article, the
notion of $\mathcal{F}$-perfect rings is introduced as a nontrial generalization of perfect rings
and A-perfect rings. A ring $R$ is said to be right $\mathcal{F}$-perfect if $F$ is projective relative
to $R$ for any $F ∈ \mathcal{F}$. We give some characterizations of $\mathcal{F}$-perfect rings. For example,
we show that a ring $R$ is right $\mathcal{F}$-perfect if and only if $\mathcal{F}$-covers of finitely generated
modules are projective. Moreover, we define $\mathcal{F}$-perfect modules and investigate some
properties of them. |
