On weakly delta-semiprimary ideals of commutative rings

Abstract

Let $R$ be a commutative ring with $ 1 \neq 0$. We recall that a proper ideal $I$ of $R$ is called a semiprimary ideal of $R$ if whenever $a,b\in R$ and $ab \in I$, then $a\in \sqrt{I}$ or $b\in \sqrt{I}$. We say $I$ is a {\it weakly semiprimary ideal} of $R$ if whenever $a,b\in R$ and $0 \not = ab \in I$, then $a\in \sqrt{I}$ or $b\in \sqrt{I}$. In this paper, we introduce a new class of ideals that is closely related to the class of (weakly) semiprimary ideals. Let $I(R)$ be the set of all ideals of $R$ and let $\delta: I(R) \rightarrow I(R)$ be a function. Then $\delta$ is called an expansion function of ideals of $R$ if whenever $L, I, J$ are ideals of $R$ with $J \subseteq I$, then $L \subseteq \delta(L)$ and $\delta(J) \subseteq \delta(I)$. Let $\delta$ be an expansion function of ideals of $R$. Then a proper ideal $I$ of $R$ (i.e., $I \not = R$) is called a ({\it $\delta$-semiprimary}) {\it weakly $\delta$-semiprimary} ideal of $R$ if ($ab \in I$) $0 \not = ab \in I$ implies $a \in \delta(I)$ or $b \in \delta(I)$. For example, let $\delta: I(R) \rightarrow I(R)$ such that $\delta(I) = \sqrt{I}$. Then $\delta$ is an expansion function of ideals of $R$ and hence a proper ideal $I$ of $R$ is a ($\delta$-semiprimary) weakly $\delta$-semiprimary ideal of $R$ if and only if $I$ is a (semiprimary) weakly semiprimary ideal of $R$. A number of results concerning weakly $\delta$-semiprimary ideals and examples of weakly $\delta$-semiprimary ideals are given.