Phantom Envelopes and -Phantom Covers of Modules
L Mao - Bulletin of the Iranian Mathematical Society, 2020 - Springer
We first prove that if a monomorphism is a phantom envelope of a left R-module, then its
cokernel is pure-projective; if R is a left coherent ring and an epimorphism is an Ext Ext …
cokernel is pure-projective; if R is a left coherent ring and an epimorphism is an Ext Ext …
Precovers and preenvelopes by phantom and Ext-phantom morphisms
L Mao - Communications in Algebra, 2016 - Taylor & Francis
A morphism f: M→ N of left R-modules is called a phantom morphism if the induced
morphism for every (finitely presented) right R-module A. Similarly, a morphism g: M→ N of …
morphism for every (finitely presented) right R-module A. Similarly, a morphism g: M→ N of …
On modules in which every finitely generated submodule is a kernel of an endomorphism
P Neishabouri, Y Tolooei, S Bagheri - Communications in Algebra, 2023 - Taylor & Francis
We study an R-module M in which every finitely generated submodule of M is a kernel of an
endomorphism of M. Such modules are called Co-epi-finite-retractable (CEFR). We also …
endomorphism of M. Such modules are called Co-epi-finite-retractable (CEFR). We also …
Existence of Covers and Envelopes of a Left Orthogonal Class and Its Right Orthogonal Class of Modules
A Umamaheswaran, R Udhayakumar… - Journal of …, 2022 - Wiley Online Library
In this paper, we investigate the notions of X⊥‐projective, X‐injective, and X‐flat modules
and give some characterizations of these modules, where X is a class of left modules. We …
and give some characterizations of these modules, where X is a class of left modules. We …
Remarks on fp-Injective and fp-Flat Modules
L Mao - Arabian Journal for Science and Engineering, 2011 - Springer
Abstract A left R-module M is said to be fp-injective if, for every monomorphism K→ L with K
and L finitely presented left R-modules, Hom (L, M)→ Hom (K, M) is an epimorphism. A right …
and L finitely presented left R-modules, Hom (L, M)→ Hom (K, M) is an epimorphism. A right …
Modules which are invariant under nilpotents of their envelopes and covers
A module is called nilpotent-invariant if it is invariant under any nilpotent endomorphism of
its injective envelope [MT Koşan and TC Quynh, Nilpotent-invaraint modules and rings …
its injective envelope [MT Koşan and TC Quynh, Nilpotent-invaraint modules and rings …
On n-phantom and n-Ext-phantom Morphisms
K Lan, B Lu - Taiwanese Journal of Mathematics, 2021 - JSTOR
This paper extends many conclusions based on phantom envelopes and Ext-phantom
covers of modules, and we find that many important properties still hold after replacing …
covers of modules, and we find that many important properties still hold after replacing …
A note on existence of envelopes and covers
J Chen, N Ding - Bulletin of the Australian Mathematical Society, 1996 - cambridge.org
We prove the following results for a ring R.(a) If C is a class of right R-modules closed under
direct summands and isomorphisms, then every right R-module has an epic C-envelope if …
direct summands and isomorphisms, then every right R-module has an epic C-envelope if …
Self-injective and PF endomorphism rings
JL García Hernández, JL Gómez Pardo - Israel Journal of Mathematics, 1987 - Springer
Self-injective and PF endomorphism rings Page 1 ISRAEL JOURNAL OF MATHEMATICS, Vol.
58, No. 3, 1987 SELF-INJECTIVE AND PF ENDOMORPHISM RINGS BY JL GARCiA …
58, No. 3, 1987 SELF-INJECTIVE AND PF ENDOMORPHISM RINGS BY JL GARCiA …
New characterizations of pseudo-coherent rings
L Mao, N Ding - 2010 - degruyter.com
Let R be a ring. A left R-module M (resp. right R-module N) is called singly injective (resp.
singly flat) if Ext1 (F/C, M)= 0 (resp. Tor1 (N, F/C)= 0) for any cyclic submodule C of any …
singly flat) if Ext1 (F/C, M)= 0 (resp. Tor1 (N, F/C)= 0) for any cyclic submodule C of any …