Countably generated flat modules are quite flat
نویسندگان
چکیده
We prove that if $R$ is a commutative Noetherian ring, then every countably generated flat $R$-module quite flat, i.e., direct summand of transfinite extension localizations in countable multiplicative subsets. also show the spectrum cardinality less than $\kappa$, where $\kappa$ an uncountable regular cardinal, modules with generators. This provides alternative proof fact over ring spectrum, all are flat. More generally, we say CFQ presented von Neumann rings and $S$-almost perfect CFQ. A zero-dimensional local only it perfect. domain its proper quotient valuation strongly discrete.
منابع مشابه
Periodic Flat Modules, and Flat Modules for Finite Groups
If R is a ring of coefficients and G a finite group, then a flat RG-module which is projective as an R-module is necessarily projective as an RG-module. More generally, if H is a subgroup of finite index in an arbitrary group Γ, then a flat RΓmodule which is projective as an RH-module is necessarily projective as an RΓ-module. This follows from a generalization of the first theorem to modules o...
متن کاملRelative Cotorsion Modules and Relative Flat Modules
Let R be a ring, M a right R-module, and n a fixed non-negative integer. M is called n-cotorsion if Extn+1 R N M = 0 for any flat right R-module N . M is said to be n-flat if ExtR M N = 0 for any n-cotorsion right R-module N . We prove that ( n n is a complete hereditary cotorsion theory, where n (resp. n) denotes the class of all n-flat (resp. n-cotorsion) right R-modules. Several applications...
متن کاملMULTIPLICATION MODULES THAT ARE FINITELY GENERATED
Let $R$ be a commutative ring with identity and $M$ be a unitary $R$-module. An $R$-module $M$ is called a multiplication module if for every submodule $N$ of $M$ there exists an ideal $I$ of $R$ such that $N = IM$. It is shown that over a Noetherian domain $R$ with dim$(R)leq 1$, multiplication modules are precisely cyclic or isomorphic to an invertible ideal of $R$. Moreover, we give a charac...
متن کاملStrongly Gorenstein projective , injective and flat modules
Let R be a ring and n a fixed positive integer, we investigate the properties of n-strongly Gorenstein projective, injective and flat modules. Using the homological theory , we prove that the tensor product of an n-strongly Gorenstein projective (flat) right R -module and projective (flat) left R-module is also n-strongly Gorenstein projective (flat). Let R be a coherent ring ,we prove that the...
متن کاملEpic Envelopes by Generalized Flat Modules
We establish equivalent conditions under which every right Rmodule has an epic X -envelope, when X is a Tor-orthogonal class of left-Rmodules. As particular cases, one may recover and complete known results on various generalizations of flatness. MSC 2000. 16D50, 16D40.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Commutative Algebra
سال: 2022
ISSN: ['1939-0807', '1939-2346']
DOI: https://doi.org/10.1216/jca.2022.14.37