3 papers
math.RA2009
Noncrossed Product Matrix Subrings and Ideals of Graded Rings
Johan Öinert, Patrik Lundström
We show that if a groupoid graded ring has a certain nonzero ideal property and the principal component of the ring is commutative, then the intersection of a nonzero twosided idea…
math.RA2009
Simple group graded rings and maximal commutativity
Johan Öinert
In this paper we provide necessary and sufficient conditions for strongly group graded rings to be simple. For a strongly group graded ring the grading…
math.RA2008
Commutativity and Ideals in Category Crossed Products
Johan Öinert, Patrik Lundström
In order to simultaneously generalize matrix rings and group graded crossed products, we introduce category crossed products. For such algebras we describe the center and the commu…