Quasiregular rings
Quasitilted algebras have preprojective components
We show that a quasitilted algebra has a preprojective component. This is proved by giving an algorithmic criterion for the existence of preprojective components.
Quillen cohomology and Baues-Wirsching cohomology of algebraic, theories
Radicals Coinciding with the Von Neumann Regular Radical on Artinian Rings.
Radicals of Regular Near Rings.
Real representations of quivers
The Dynkin and the extended Dynkin graphs are characterized by representations over the real numbers.
Realizing maps between modules over Tate cohomology rings.
Recognizing dualizing complexes
Let A be a noetherian local commutative ring and let M be a suitable complex of A-modules. It is proved that M is a dualizing complex for A if and only if the trivial extension A ⋉ M is a Gorenstein differential graded algebra. As a corollary, A has a dualizing complex if and only if it is a quotient of a Gorenstein local differential graded algebra.
Recollements induced by good (co)silting dg-modules
Let be a dg--module, the endomorphism dg-algebra of . We know that if is a good silting object, then there exist a dg-algebra and a recollement among the derived categories of , of and of . We investigate the condition under which the induced dg-algebra is weak nonpositive. In order to deal with both silting and cosilting dg-modules consistently, the notion of weak silting dg-modules is introduced. Thus, similar results for good cosilting dg-modules are obtained. Finally, some...
Reflexive algebras and sigma algebras.
Reflexive and dihedral (co)homology of a pre-additive category.
Regular additively inverse semirings.
Regular Rings and Baer Rings.
Regularity of semigroup rings.
Regularity of the four dimensional Sklyanin algebra
Relative theory in subcategories
We generalize the relative (co)tilting theory of Auslander-Solberg in the category mod Λ of finitely generated left modules over an artin algebra Λ to certain subcategories of mod Λ. We then use the theory (relative (co)tilting theory in subcategories) to generalize one of the main result of Marcos et al. [Comm. Algebra 33 (2005)].
Relative weak derived functors
Let be a ring, a fixed non-negative integer, the class of all left -modules with weak injective dimension at most , and the class of all right -modules with weak flat dimension at most . Using left (right) -resolutions and the left derived functors of Hom we study the weak injective dimensions of modules and rings. Also we prove that is right balanced on by , and investigate the global right -dimension of by right derived functors of .
Remarks on strongly regular rings
Representation of algebraic distributive lattices with ℵ1 compact elements as ideal lattices of regular rings.
We prove the following result: Theorem. Every algebraic distributive lattice D with at most ℵ1 compact elements is isomorphic to the ideal lattice of a von Neumann regular ring R.(By earlier results of the author, the ℵ1 bound is optimal.) Therefore, D is also isomorphic to the congruence lattice of a sectionally complemented modular lattice L, namely, the principal right ideal lattice of R. Furthermore, if the largest element of D is compact, then one can assume that R is unital, respectively,...
Representation theory of two-dimensionalbrauer graph rings
We consider a class of two-dimensional non-commutative Cohen-Macaulay rings to which a Brauer graph, that is, a finite graph endowed with a cyclic ordering of edges at any vertex, can be associated in a natural way. Some orders Λ over a two-dimensional regular local ring are of this type. They arise, e.g., as certain blocks of Hecke algebras over the completion of at (p,q-1) for some rational prime . For such orders Λ, a class of indecomposable maximal Cohen-Macaulay modules (see introduction)...