{"title":"On overrings of a domain","authors":"H. Butts, N. Vaughan","doi":"10.32917/HMJ/1206138590","DOIUrl":null,"url":null,"abstract":"Throughout this paper D will denote an integral domain with 1^0 and quotient field X, and by an overring of D will be meant a ring / such that DczJczK. An ideal A of D is called a valuation ideal provided there exists a valuation overring Dv of D such that ADV nD = A ([22; 340], [10]). If 77 is a general ring property, then we shall refer to an ideal A of D as a Π-ideal provided there exists an overring / of D such that / is a 77-domain (i.e. / has the property 77) and A = AJπD. It is shown in [10] that if every principal ideal of D is a valuation ideal, then D is a valuation ring. Furthermore, if every proper ideal of D is a Dedekind ideal, then D is a Dedekind domain [2] and if every proper ideal of D is a Prufer ideal, then D is a Prufer domain [7], [10; 238]. In this paper we are mainly concerned with the following question. When does the statement (a) \"there exists a collection d of 77-ideals of 7)\" imply the statement (b) \"D is a 77-domain\" (i.e. D has property 77)? Our main result in this direction is that (a) implies (b) when \"77-domain\" = \"Krull domain\" and d is the collection of proper principal ideals of 7), i.e. if every proper principal ideal is a Krull ideal, then D is a Krull domain. The same result holds in case \"Krull domain is replaced by either \"integrally closed domain\" or \"completely integrally closed domain\". In addition we show that (a) implies (b) when d is the collection of proper finitely generated ideals of D and 77 is any of the following ring properties: Prufer, 1-dim. Prufer, almost Dedekind, or Dedekind. We remark that (a) does not always imply (b), even in the case that d is the set of all ideals of D (e.g. if 77 is one of P.I.D., Bezout, or (λR-propertysee Section 5). In general we use the notation and terminology of [21] and [22]. In particular, c denotes containment, while < denotes proper containment and A is a proper ideal of D provided (0)<A<D. The theorems considered in this paper are trivial in case D is a field, so we assume throughout that D has at least one proper ideal. We wish to thank Paul M. Eakin Jr. for suggesting Lemma 3.1 (allowing us to shorten some proofs in Section 3) and Proposition 5.1 to us.","PeriodicalId":17080,"journal":{"name":"Journal of science of the Hiroshima University Ser. A Mathematics, physics, chemistry","volume":"33 1","pages":"95-104"},"PeriodicalIF":0.0000,"publicationDate":"1969-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of science of the Hiroshima University Ser. A Mathematics, physics, chemistry","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.32917/HMJ/1206138590","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 4
Abstract
Throughout this paper D will denote an integral domain with 1^0 and quotient field X, and by an overring of D will be meant a ring / such that DczJczK. An ideal A of D is called a valuation ideal provided there exists a valuation overring Dv of D such that ADV nD = A ([22; 340], [10]). If 77 is a general ring property, then we shall refer to an ideal A of D as a Π-ideal provided there exists an overring / of D such that / is a 77-domain (i.e. / has the property 77) and A = AJπD. It is shown in [10] that if every principal ideal of D is a valuation ideal, then D is a valuation ring. Furthermore, if every proper ideal of D is a Dedekind ideal, then D is a Dedekind domain [2] and if every proper ideal of D is a Prufer ideal, then D is a Prufer domain [7], [10; 238]. In this paper we are mainly concerned with the following question. When does the statement (a) "there exists a collection d of 77-ideals of 7)" imply the statement (b) "D is a 77-domain" (i.e. D has property 77)? Our main result in this direction is that (a) implies (b) when "77-domain" = "Krull domain" and d is the collection of proper principal ideals of 7), i.e. if every proper principal ideal is a Krull ideal, then D is a Krull domain. The same result holds in case "Krull domain is replaced by either "integrally closed domain" or "completely integrally closed domain". In addition we show that (a) implies (b) when d is the collection of proper finitely generated ideals of D and 77 is any of the following ring properties: Prufer, 1-dim. Prufer, almost Dedekind, or Dedekind. We remark that (a) does not always imply (b), even in the case that d is the set of all ideals of D (e.g. if 77 is one of P.I.D., Bezout, or (λR-propertysee Section 5). In general we use the notation and terminology of [21] and [22]. In particular, c denotes containment, while < denotes proper containment and A is a proper ideal of D provided (0)