|
广西师范大学学报(自然科学版) ›› 2020, Vol. 38 ›› Issue (1): 47-53.doi: 10.16088/j.issn.1001-6600.2020.01.006
王茜1,2*, 王芳贵2, 沈磊2
WANG Xi1,2*, WANG Fanggui2, SHEN Lei2
摘要: 本文引入并研究了${\ell}$n-平坦模。设R是任何环, n是非负整数, 称右R-模M是${\ell}$n-平坦模, 类指对任何n-余挠左R-模C, 都有TorR1(M,C)=0。本文证明了M是平坦模当且仅当M是${\ell}$n-平坦模且fdRM≤1, ${\ell}$n-平坦模对纯子模以及其对应的纯商模封闭;还证明了C-平坦模与C1-平坦模就是平坦模, 并且当R是整环时, 无挠的C2-平坦模也是平坦模; R的弱整体维数不超过n当且仅当任意右R-模的第n次合冲是${\ell}$n-平坦模;R是von Neumann正则环当且仅当每个右R-模是${\ell}$n-平坦模。
中图分类号:
[1] 王芳贵. 交换环与星型算子理论[M].北京:科学出版社, 2006. [2] DING N Q, CHEN J L. On copure flat modules and flat resolvents[J].Communications in Algebra,1996,24(3):1071-1081. [3] FU X H, DING N Q. On strongly copure flat modules and copure flat dimensions[J].Communications in Algebra,2010,38(12): 4531-4544. [4] MAO L X, DING N Q. Relative copure injective and copure flat modules[J].Journal of Pure and Applied Algebra, 2007,208(2): 635-646. [5] ENOCHS E E, JENDA O M G. Copure injective modules[J].Quaestiones Mathematical,1991,14(14): 401-409. [6] ENOCHS E E, JENDA O M G. Copure injective resolusions, flat resolvents and dimensions[J].Commentationes Mathematicae Universitatis Carolinae,1993,34(2): 203-211. [7] HARRISON D K. Infinite Abelian groups and homological methods[J].Annals of Mathematics,1959,69(2): 366-391. [8] FUCHS L. Cotorsion modules over noetherian hereditary rings[J].Houston Journal of Mathematics,1981,3(1): 33-46. [9] ENOCHS E E, ROZAS J R G, OYONARTE L. Finitely generated cotorsion modules[J].Proceedings of the Edinburgh Mathematical Society,2001,44(1): 143-152. [10]COUCHOT F. Commutative rings whose cotorsion modules are pure-injective[J].Palestine Journal of Mathematics,2016,5(1): 81-89. [11]XU J Z. Flat cover of modules[C]//Lecture Notes in Mathematics, 1634. Berlin: Springer, 1996. [12]MAO L X, DING N Q. The cotorsion dimension of modules and rings[C]//Lecture Notes in Pure and Applied Mathematics, Boca Raton, FL:Chapman & Hall/CRC,2006: 57-73. [13]ENOCHS E E, HUANG Z Y. Injective envelopes and (Gorenstein) flat covers[J].Algebras and Representation Theory,2012,15(6): 1131-1145. [14]熊涛. 模类Fn确定的同调理论及其应用[D].成都: 四川师范大学, 2016. [15]王茜, 王芳贵, 何可. ${\ell}$n-内射模及其刻画[J].四川师范大学学报(自然科学版), 2017, 40(5): 588-592. [16]GöBEL R, TRLIFAJ J. Approximations and endomorphism algebras of modules[M].Berlin: Walter de Gruyter, 2006. [17]FIELDHOUSE D J. Character modules, dimension and purity[J].Glasgow Mathematical Journal,1972,13(2): 144-146. [18]ROTMAN J J. An introduction to homological algebra[M].London: Academic Press,1979. [19]BASS H. Finitistic dimension and a homological generalization of semi-primary rings[J].Transactions of the American Mathematical Society,1960,95(3): 466-488. [20]LEE S B. Weak-injective modules[J]. Communications in Algebra,2006,34(1): 361-370. |
[1] | 梁春梅, 王芳贵, 吴小英. 分次单内射模及其刻画[J]. 广西师范大学学报(自然科学版), 2019, 37(2): 113-120. |
[2] | 刘天莉莲, 王芳贵, 高增辉. FI-gr-内射模[J]. 广西师范大学学报(自然科学版), 2019, 37(1): 155-164. |
|
版权所有 © 广西师范大学学报(自然科学版)编辑部 地址:广西桂林市三里店育才路15号 邮编:541004 电话:0773-5857325 E-mail: gxsdzkb@mailbox.gxnu.edu.cn 本系统由北京玛格泰克科技发展有限公司设计开发 |