Higher order derivations of modules
Homological dimensions and approximate contractibility for Köthe algebras
We give a survey of our recent results on homological properties of Köthe algebras, with an emphasis on biprojectivity, biflatness, and homological dimension. Some new results on the approximate contractibility of Köthe algebras are also presented.
Homological Methods Applied to the Derived Series of Groups
Inertial law of symplectic forms on modules over plural algebra
In this paper the problem of construction of the canonical matrix belonging to symplectic forms on a module over the so called plural algebra (introduced in [5]) is solved.
Injective and projective near-ring modules
Injective and projective properties of -modules
We study whether the projective and injective properties of left -modules can be implied to the special kind of left -modules, especially to the case of inverse polynomial modules and Laurent polynomial modules.
Intertial Subalgebras over Hensel Rings.
Kaplansky classes
Locally free modules
Mittag-Leffler modules, reduced products, and direct products
Modules projectifs sur un ordre
Modules quasi-projectifs, projectifs et parfaits
Modules which are epi-equivalent to projective modules
Modules with the direct summand sum property
The present work gives some characterizations of -modules with the direct summand sum property (in short DSSP), that is of those -modules for which the sum of any two direct summands, so the submodule generated by their union, is a direct summand, too. General results and results concerning certain classes of -modules (injective or projective) with this property, over several rings, are presented.
Moduln, die in jeder Erweiterung ein Komplement haben.
-flat and -FP-injective modules
In this paper, we study the existence of the -flat preenvelope and the -FP-injective cover. We also characterize -coherent rings in terms of the -FP-injective and -flat modules.
--coherent rings and Gorenstein graded modules
Let be a graded ring and be an integer. We introduce and study the notions of Gorenstein -FP-gr-injective and Gorenstein -gr-flat modules by using the notion of special finitely presented graded modules. On -gr-coherent rings, we investigate the relationships between Gorenstein -FP-gr-injective and Gorenstein -gr-flat modules. Among other results, we prove that any graded module in -gr (or gr-) admits a Gorenstein -FP-gr-injective (or Gorenstein -gr-flat) cover and preenvelope, respectively....
Neue Charakterisierungen von Artinschen Moduln und hereditären Ringen
Non-perfect rings and a theorem of Eklof and Shelah
We prove a stronger form, , of a consistency result, , due to Eklof and Shelah. concerns extension properties of modules over non-left perfect rings. We also show (in ZFC) that does not hold for left perfect rings.
Normal radicals of endomorphism rings of free and projective modules