An alternate criterion of colocalized-localized modules.
The aim of this note is to express a module which is localized as well as colocalized in terms of an object of an intersecting subcategory related to static modules.
Partially flat and projective modules.
Assume that A and B are rings with identity and that M and N are (B,A) and (A,B) bimodules respectively. We say that AN (respt. MA) is
A class of zero divisor rings in which every graph is precisely the union of a complete graph and a complete bipartite graph
Recently, an interest is developed in estimating genus of the zero-divisor graph of a ring. In this note we investigate genera of graphs of a class of zero-divisor rings (a ring in which every element is a zero divisor). We call a ring R to be right absorbing if for a; b in R, ab is not 0, then ab D a. We first show that right absorbing rings are generalized right Klein 4-rings of characteristic two and that these are non-commutative zero-divisor local rings. The zero-divisor graph of such a ring...
The number of complete exceptional sequences for a Dynkin algebra
The Dynkin algebras are the hereditary artin algebras of finite representation type. The paper determines the number of complete exceptional sequences for any Dynkin algebra. Since the complete exceptional sequences for a Dynkin algebra of Dynkin type Δ correspond bijectively to the maximal chains in the lattice of non-crossing partitions of type Δ, the calculations presented here may also be considered as a categorification of the corresponding result for non-crossing partitions.
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