Quasi-injective modules;
uniform modules;
von Neumann regular rings;
serial rings;
Kuppisch series;
essentially relative injectivity;
almost relative injectivity;
D O I:
10.1090/conm/738/14884
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
Let M be a quasi-injective module and S be its ring of endomorphisms. It is well known that the radical J of S is the set of all those endomorphisms of M which have large kernels, and S/J is a von Neumann regular ring. Such a result does not hold for almost self-injective modules. Let N be an almost self-injective module and G its ring of endomorphisms. By enlarging the ring of endomorphisms of N, it is shown that a generalization of the above result for quasi-injective modules can be given for N. In addition an artinian serial ring R with no non-trivial central idempotent is studied. A characterization for R to be almost right self-injective in terms of its Kuppisch series is given, which can help in creating certain types of almost self-injective rings.