Special precovering classes in comma categories
J Hu, H Zhu - Science China Mathematics, 2022 - Springer
… not only give rise to adjoint functors for constructing recollements … modules, complete
cotorsion pairs make it possible to produce special preenvelopes once we know special precovers …
cotorsion pairs make it possible to produce special preenvelopes once we know special precovers …
fpn-injective and fpn-flat modules
J Wei, Y Zhang - Georgian Mathematical Journal, 2015 - degruyter.com
… preenvelope). We also study the exchange properties of … with ∈ C is a monic C-precover
of , then it is a monic C-cover of … As to the second claim, note that we have an adjoint …
of , then it is a monic C-cover of … As to the second claim, note that we have an adjoint …
Approximations by maximal Cohen–Macaulay modules
H Holm - Pacific Journal of Mathematics, 2015 - msp.org
… module has a special maximal CM precover. In this paper, we prove the existence of special
maximal CM preenvelopes … , which we claim is a left adjoint of the inclusion G : MCM → mod…
maximal CM preenvelopes … , which we claim is a left adjoint of the inclusion G : MCM → mod…
[PDF][PDF] APPROXIMATIONS OF MODULES (LECTURE NOTES FOR NMAG531)
JAN TRLIFAJ - 2023 - karlin.mff.cuni.cz
… This fact – discovered by Salce [34] – says that the mutually dual categorical notions of a
special precover and a special preenvelope are tied up by the homological tie of a cotorsion …
special precover and a special preenvelope are tied up by the homological tie of a cotorsion …
Covers and direct limits: a contramodule-based approach
S Bazzoni, L Positselski - Mathematische Zeitschrift, 2021 - Springer
… -modules. Subsequently, in 1981 Enochs proved that any precovering class of modules closed
… L\) can be naturally extended to a pair of adjoint functors \(\Phi :\mathsf B\longrightarrow \…
… L\) can be naturally extended to a pair of adjoint functors \(\Phi :\mathsf B\longrightarrow \…
Cotorsion pairs and approximation classes over formal triangular matrix rings
L Mao - Journal of Pure and Applied Algebra, 2020 - Elsevier
… is devoted to preenvelopes and precovers of modules over a … of left A-modules and D be a
class of left B-modules, we prove … to see that p is a left adjoint of q and h is a right adjoint of q. …
class of left B-modules, we prove … to see that p is a left adjoint of q and h is a right adjoint of q. …
On exact categories and applications to triangulated adjoints and model structures
M Saorín, J Šťovíček - Advances in Mathematics, 2011 - Elsevier
… module categories. In particular we prove that every deconstructible class of modules is
precovering… M is necessarily an X-precover while the inflation M ↣ Y is a Y-preenvelope. We will …
precovering… M is necessarily an X-precover while the inflation M ↣ Y is a Y-preenvelope. We will …
Absolutely s-Pure Modules and Neat-Flat Modules
E Büyükaşık, Y Durğun - Communications in Algebra, 2015 - Taylor & Francis
… The rings whose simple right modules have a projective preenvelope are … homomorphism
φ: A → M is an ℳ-precover of M if A ∈ ℳ and the abelian … by the standard adjoint isomorphism. …
φ: A → M is an ℳ-precover of M if A ∈ ℳ and the abelian … by the standard adjoint isomorphism. …
[PDF][PDF] On mininjective and min-flat modules
LX Mao - Publ. Math. Debrecen, 2008 - scholar.archive.org
… A C-precover φ : C → M of M is said to be a C-cover if every … Dually we have the definitions
of a C-preenvelope and a C-… precovers and the cokernels of min-flat preenvelopes, we …
of a C-preenvelope and a C-… precovers and the cokernels of min-flat preenvelopes, we …
Gorenstein flat precovers and Gorenstein injective preenvelopes in Grothendieck categories
E Enochs, JR García Rozas, L Oyonarte, B Torrecillas - 2019 - projecteuclid.org
… ) in this category to be precovering, we need the class of flat discrete modules to be closed
… tensor product of modules) is precovering (see [2, Corollary 4.8]). Our type of precovers are …
… tensor product of modules) is precovering (see [2, Corollary 4.8]). Our type of precovers are …