A commutative ring R is called extending if every ideal is essential in a direct summand of RR. The following results are proved： （1） C（X） is an extending ring if and only if X is extremely disconnected; （2） S...A commutative ring R is called extending if every ideal is essential in a direct summand of RR. The following results are proved： （1） C（X） is an extending ring if and only if X is extremely disconnected; （2） Spec（R） is extremely disconnected and R is semiprime if and only if R is a nonsingular extending ring; （3） Spec（R） is extremely disconnected if and only if R/N（R） is an extending ring, where N（R） consists of all nilpotent elements of R. As an application, it is also shown that any Gelfand nonsingular extending ring is clean.展开更多
In this paper,we study extended modules for a special class of Oreextensions.We will assume that R is a ring and A will denote the Ore extensionA:=R[X1,...,xn;σ]for whichσis an automorphism of R,xixj=xjxi and xir=σ...In this paper,we study extended modules for a special class of Oreextensions.We will assume that R is a ring and A will denote the Ore extensionA:=R[X1,...,xn;σ]for whichσis an automorphism of R,xixj=xjxi and xir=σ(r)xi,for every 1<i,j≤n.With some extra conditions over the ring R,wewill prove Vaserstein's,Quillen's patching,Horrocks',and Quillen-Suslin's theoremsfor this type of non-commutative rings.展开更多
基金supported by National Natural Science Foundation of China (10671122)supported by Collegial Natural Science Research Program of Education Department of Jiangsu Province (07KJD110179)
文摘A commutative ring R is called extending if every ideal is essential in a direct summand of RR. The following results are proved： （1） C（X） is an extending ring if and only if X is extremely disconnected; （2） Spec（R） is extremely disconnected and R is semiprime if and only if R is a nonsingular extending ring; （3） Spec（R） is extremely disconnected if and only if R/N（R） is an extending ring, where N（R） consists of all nilpotent elements of R. As an application, it is also shown that any Gelfand nonsingular extending ring is clean.
基金the project New trends of non-commutative algebra and skew PBW extensions,HERMES CODE 26872,Universidad Nacional de ColombiaThe authors are grateful tothe editors and the referee for valuable suggestions and corrections.
文摘In this paper,we study extended modules for a special class of Oreextensions.We will assume that R is a ring and A will denote the Ore extensionA:=R[X1,...,xn;σ]for whichσis an automorphism of R,xixj=xjxi and xir=σ(r)xi,for every 1<i,j≤n.With some extra conditions over the ring R,wewill prove Vaserstein's,Quillen's patching,Horrocks',and Quillen-Suslin's theoremsfor this type of non-commutative rings.
