Fuzzy projective modules and tensor products in fuzzy module categories

Abstract

Let $R$ be a commutative ring. We write $mbox{Hom}(mu_A, nu_B)$ for the set of all fuzzy $R$-morphisms from $mu_A$ to $nu_B$, where $mu_A$ and $nu_B$ are two fuzzy $R$-modules. We make<br />$mbox{Hom}(mu_A, nu_B)$ into fuzzy $R$-module by redefining a function $alpha:mbox{Hom}(mu_A, nu_B)longrightarrow [0,1]$. We study the properties of the functor $mbox{Hom}(mu_A,-):FRmbox{-Mod}rightarrow FRmbox{-Mod}$ and get some unexpected results. In addition, we prove that<br />$mbox{Hom}(xi_p,-)$ is exact if and only if $xi_P$ is a fuzzy projective $R$-module, when $R$ is a commutative semiperfect ring.<br />Finally, we investigate tensor product of two fuzzy $R$-modules and get some related properties. Also, we study the relationships between Hom functor and tensor functor.