Big projective modules are free

H Bass - Illinois Journal of Mathematics, 1963 - projecteuclid.org
More precisely, cll n R-module P uniformly-big, where b is n infinite crdinl, if (i) P cn be
generated by b elements, nd (ii) PlOP requires generators for ll two-sided ideals R). A free …

On the purity of the branch locus

M Auslander - American Journal of Mathematics, 1962 - JSTOR
Let R be a regular local ring with field of quotients K, let L be a finite separable field
extension of K and S the localization of the integral closure of R in L at some maximal ideal …

Direct products of modules

SU Chase - Transactions of the American Mathematical Society, 1960 - JSTOR
1. Introduction. It is a well-known and basic result of homological alge-bra that the direct
product of an arbitrary family of injective modules over any ring is again injective [3, p. 8] …

[引用][C] Pure submodules of direct products of free modules

B Zimmermann-Huisgen - Mathematische Annalen, 1976 - Springer
We start by considering the following three problems for a right R-module M= MR where R is
an associative ring with 1:(1) Characterize the modules M with the following property …

Projective ideals of finite type

WW Smith - Canadian Journal of Mathematics, 1969 - cambridge.org
The main results in this paper relate the concepts of flatness and projectiveness for finitely
generated ideals in a commutative ring with unity. In this discussion the idea of a …

Strongly flat covers

S Bazzoni, L Salce - Journal of the London Mathematical Society, 2002 - cambridge.org
It is proved that all modules over an integral domain have strongly flat cover if and only if
every flat-module is strongly flat. The domains satisfying this property are characterized by …

[引用][C] On quasi-projective modules via relative projectivity

KR Fuller, DA Hill - Archiv der Mathematik, 1970 - Springer
Recently,]~. DE ROBERT has considered the dual concepts of relative projectivity and
relative injectivity that extend the notions of quasi-projective and quasi-injective modules …

Powers of the phantom ideal

XH Fu, I Herzog - Proceedings of the London Mathematical …, 2016 - academic.oup.com
The mono-epi (ME) exact structure on the morphisms of an exact category is introduced and
used to prove ideal versions of Salce's Lemma, Christensen's (Ghost) Lemma, and …

On flat modules over commutative rings

S Endo - Journal of the Mathematical Society of Japan, 1962 - jstage.jst.go.jp
It is well-known that if R is a Noetherian ring or a local ring, then every finitely generated flat
R-module is projective (cf.(1),(3), R need not be commutative.). It is also known that if R is a …

On injective modules and flat modules

T Ishikawa - Journal of the Mathematical Society of Japan, 1965 - jstage.jst.go.jp
In this paper we will first establish a duality between in jectivity and flatness for modules.
That is: Let E be a faithfully in jective module". Then, for each module A, we have W, dim. A …