Submodules of pseudo semi-projective modules
Abstract
A module M is called pseudo semi-projective if, for all endomorphisms α,β of M with Im(α)=Im(β), then αEnd(M)=βEnd(M). In this paper, we study submodules of pseudo semi-projective modules. It is shown that if every (finitely generated) submodule of a semiprojective right R-module is pseudo semi-projective, then every factor ring of R is right (semi-)hereditary. Moreover, we show that if R is left perfect and finitely generated submodules of pseudo semi-projective right R-modules are pseudo semi-projective, then R has a decomposition of abelian groups Rℤ=S⊕J(R), where S is a semisimple subring of R containing 1.
Communicated by A. Umar