Displaying 41 – 60 of 129

Showing per page

Full matrix algebras with structure systems

Hisaaki Fujita (2003)

Colloquium Mathematicae

We study associative, basic n × n𝔸-full matrix algebras over a field, whose multiplications are determined by structure systems 𝔸, that is, n-tuples of n × n matrices with certain properties.

Loewy coincident algebra and Q F -3 associated graded algebra

Hiroyuki Tachikawa (2009)

Czechoslovak Mathematical Journal

We prove that an associated graded algebra R G of a finite dimensional algebra R is Q F (= selfinjective) if and only if R is Q F and Loewy coincident. Here R is said to be Loewy coincident if, for every primitive idempotent e , the upper Loewy series and the lower Loewy series of R e and e R coincide. Q F -3 algebras are an important generalization of Q F algebras; note that Auslander algebras form a special class of these algebras. We prove that for a Loewy coincident algebra R , the associated graded algebra...

Morita duality for Grothendieck categories.

José L. Gómez Pardo, Francisco de A. Guil Asensio (1992)

Publicacions Matemàtiques

We survey some recent results on the theory of Morita duality for Grothendieck categories, comparing two different versions of this concept, and giving applications to QF-3 and Qf-3' rings.

Non-perfect rings and a theorem of Eklof and Shelah

Jan Trlifaj (1991)

Commentationes Mathematicae Universitatis Carolinae

We prove a stronger form, A + , of a consistency result, A , due to Eklof and Shelah. A + concerns extension properties of modules over non-left perfect rings. We also show (in ZFC) that A does not hold for left perfect rings.

On certain classes of modules.

Kalathoor Varadarajan (1992)

Publicacions Matemàtiques

Let X be a class or R-modules containing 0 and closed under isomorphic images. With any such X we associate three classes ΓX, FX and ΔX. The study of some of the closure properties of these classes allows us to obtain characterization of Artinian modules dualizing results of Chatters. The theory of Dual Glodie dimension as developed by the author in some of his earlier work plays a crucial role in the present paper.

On generalization of injectivity

Roger Yue Chi Ming (1992)

Archivum Mathematicum

Characterizations of quasi-continuous modules and continuous modules are given. A non-trivial generalization of injectivity (distinct from p -injectivity) is considered.

On p -injectivity, YJ-injectivity and quasi-Frobeniusean rings

Roger Yue Chi Ming (2002)

Commentationes Mathematicae Universitatis Carolinae

A new characteristic property of von Neumann regular rings is proposed in terms of annihilators of elements. An ELT fully idempotent ring is a regular ring whose simple left (or right) modules are either injective or projective. Artinian rings are characterized in terms of Noetherian rings. Strongly regular rings and rings whose two-sided ideals are generated by central idempotents are characterized in terms of special annihilators. Quasi-Frobeniusean rings are characterized in terms of p -injectivity....

Currently displaying 41 – 60 of 129