Abstract:
In this paper we introduce some lattices of classes of left
R-module relative to a preradical sigma. These lattices are generaliza-
tions of the lattices R-TORS, R-tors, R-nat, R-conat, of torsion theo-
ries, hereditary torsion theories, natural classes and conatural classes,
respectively. We define the lattices σ-(R-TORS), σ-(R-tors), σ-(R-nat),
σ-(R-conat), which reduce to the lattices mentioned above, when one
takes sigma as the identity. We characterize the equality between these
lattices by means of the (σ-HH) condition, which we introduce. We also
present some results about σ-retractable rings, σ-Max rings extending
results about Mod-retractable rings and Max rings.
Type of Study:
Research paper |
Subject:
Special