EUDML

Let $D$ be an integral domain with quotient field $D$ . Recall that $D$ is Schreier if $D$ is integrally closed and for all $x,y,z\in D\setminus\{0\}$ , $x|yz$ implies that $x=r\cdot s$ where $r|y$ e $s|z$ . A GCD domain is Schreier. We show that an integral domain $D$ is a GCD domain if and only if (i) for each pair $a,b\in D\setminus\{0\}$ , there is a finitely generated ideal $B$ such that $aD\bigcap bD=B_{v}$ and (ii) every quadratic in $D[X]$ that is a product of two linear polynomials in $K[X]$ is a product of two linear polynomials in $D[X]$ . We also show that $D$ is Schreier if and only if every polynomial...

Star operations in extensions of integral domains

David F. Anderson; Said El Baghdadi; Muhammad Zafrullah — 2010

Actes des rencontres du CIRM

An extension $D \subseteq R$ of integral domains is $t$ - (resp., $t$ -) if ${(I R)}^{- 1} = {(I^{- 1} R)}_{v}$ (resp., ${(I R)}_{v} = {(I_{v} R)}_{v})$ for every nonzero finitely generated fractional ideal $I$ of $D$ . We show that strongly $t$ -compatible implies $t$ -compatible and give examples to show that the converse does not hold. We also indicate situations where strong $t$ -compatibility and its variants show up naturally. In addition, we study integral domains $D$ such that $D \subseteq R$ is strongly $t$ -compatible (resp., $t$ -compatible) for every overring $R$ of $D$ .