Let A be a ring.In this paper we generalize some results introduced by Aliabad and Mohamadian.We give a relation bet ween the z-ideals of A and t hose of the formal power series rings in an infinite set of indetermiii...Let A be a ring.In this paper we generalize some results introduced by Aliabad and Mohamadian.We give a relation bet ween the z-ideals of A and t hose of the formal power series rings in an infinite set of indetermiiiates over A.Consider A[[Xa]]3 and its subrings A[[X_(A)]]_(1),A[[X_(A)]]_(2),and A[[X_(A)]]_(α),where a is an infinite cardinal number.In fact,a z-ideal of the rings defined above is of the form I+(X_(A))i,where i=1,2,3 or an infinite cardinal number and I is a z-ideal of A.In addition,we prove that the same condition given by Aliabad and Mohamadian can be used to get a relation between the minimal prime ideals of the ring of the formal power series in an infinite set of indeterminates and those of the ring of coefficients.As a natural result,we get a relation between the z°-ideals of the formal power series ring in an infinite set of indeterminates and those of the ring of coefficients.展开更多
It is well known that every prime ideal minimal over a z-ideal is also a z-ideal. The converse is also well known in C（X）. Thus whenever I is an ideal in C（X）, then √I is a z-ideal if and only if I is, in which c...It is well known that every prime ideal minimal over a z-ideal is also a z-ideal. The converse is also well known in C（X）. Thus whenever I is an ideal in C（X）, then √I is a z-ideal if and only if I is, in which case √I = I. We show the same fact for z^-ideals and then it turns out that the sum of a primary ideal and a z-ideal （z^o-ideal） in C（X） which are not in a chain is a prime z-ideal （z^o-ideal）. We also show that every decomposable z-ideal （z^o-ideal） in C（X） is the intersection of a finite number of prime z-ideals （z^o-ideal）. Some counter-examples in general rings and some characterizations for the largest （smallest） z-ideal and z^o-ideal contained in （containing） an ideal are given.展开更多
文摘Let A be a ring.In this paper we generalize some results introduced by Aliabad and Mohamadian.We give a relation bet ween the z-ideals of A and t hose of the formal power series rings in an infinite set of indetermiiiates over A.Consider A[[Xa]]3 and its subrings A[[X_(A)]]_(1),A[[X_(A)]]_(2),and A[[X_(A)]]_(α),where a is an infinite cardinal number.In fact,a z-ideal of the rings defined above is of the form I+(X_(A))i,where i=1,2,3 or an infinite cardinal number and I is a z-ideal of A.In addition,we prove that the same condition given by Aliabad and Mohamadian can be used to get a relation between the minimal prime ideals of the ring of the formal power series in an infinite set of indeterminates and those of the ring of coefficients.As a natural result,we get a relation between the z°-ideals of the formal power series ring in an infinite set of indeterminates and those of the ring of coefficients.
基金Institute for Studies in Theoretical Physics and Mathematics(IPM),Tehran
文摘It is well known that every prime ideal minimal over a z-ideal is also a z-ideal. The converse is also well known in C（X）. Thus whenever I is an ideal in C（X）, then √I is a z-ideal if and only if I is, in which case √I = I. We show the same fact for z^-ideals and then it turns out that the sum of a primary ideal and a z-ideal （z^o-ideal） in C（X） which are not in a chain is a prime z-ideal （z^o-ideal）. We also show that every decomposable z-ideal （z^o-ideal） in C（X） is the intersection of a finite number of prime z-ideals （z^o-ideal）. Some counter-examples in general rings and some characterizations for the largest （smallest） z-ideal and z^o-ideal contained in （containing） an ideal are given.
