Article
Kyungpook Mathematical Journal 2024; 64(4): 607-618
Published online December 31, 2024 https://doi.org/10.5666/KMJ.2024.64.4.607
Copyright © Kyungpook Mathematical Journal.
Uniformly S-Projective Modules and Uniformly S-Projective Uniformly S-Covers
Hwankoo Kim*, Najib Mahdou, El Houssaine Oubouhou, Xiaolei Zhang
Division of Computer Engineering, Hoseo University, Asan 31499, Republic of Korea
e-mail: hkkim@hoseo.edu
Department of Mathematics, Faculty of Science and Technology of Fez, Box 2202,
University S.M. Ben Abdellah Fez, Morocco
e-mail: mahdou@hotmail.com
Department of Mathematics, Faculty of Science and Technology of Fez, Box 2202,
University S.M. Ben Abdellah Fez, Morocco
e-mail: hossineoubouhou@gmail.com
School of Mathematics and Statistics, Shandong University of Technology, Zibo 255049, China
e-mail: zxlrghj@163.com
Received: December 31, 2023; Revised: September 17, 2024; Accepted: September 17, 2024
Recently, Zhang and Qi introduced and studied the concept of uniformly S-projective (u-S-projective) modules, where S represents a multiplicative subset of a ring. In this paper, we first derive a u-S version of the well-known result that a module is projective if and only if it is a direct summand of a free module. We then provide a characterization of u-S-projective modules in terms of projective modules, specifically when S is regular, and then extend the projective basis lemma to the u-S setting. Finally, we show that a u-S-projective u-S-cover is characterized by a u-S-superfluous submodule, analogous to the way a projective cover is characterized by a superfluous submodule.
Keywords: u-S-exact sequence, u-S-isomorphism, u-S-projective module