On Direct Sums of Lifting Modules and Internal Exchange Property

  • Dejun, Wu (Department of Applied Mathematics, Lanzhou University of Technology)
  • Received : 2003.11.19
  • Published : 2006.03.23

Abstract

Let R be a ring with identity and let $M=M_1{\bigoplus}M_2$ be an amply supplemented R-module. Then it is proved that $M_i$ has ($D_1$) and is $M_j-^*ojective$ for $i{\neq}j$, i = 1, 2, if and only if for any coclosed submodule X of M, there exist $M\acute{_1}{\leq}M_1$ and $M\acute{_2}{\leq}M_2$ such that $M=X{\bigoplus}M\acute{_1}{\bigoplus}M\acute{_2}$.

Keywords

References

  1. D. Keskin, On lifting modules, Comm. Algebra, 28(7)(2000), 3427-3440. https://doi.org/10.1080/00927870008827034
  2. D. Keskin, Diserete and quasi-discrete modules, Comm. Algebra, 30(11)(2002), 5273-5282. https://doi.org/10.1081/AGB-120015652
  3. S. H. Mohamed and B. J. Muller, Ojective modules, Comm. Algebra, 30(4)(2002), 1817-1827. https://doi.org/10.1081/AGB-120013218
  4. S. H. Mohamed and B. J. Muller, Cojective modules, prepint.
  5. H. Hanada, J. Kado and K. Oshiro, On direct sums of extending modules and internal exchange property, Proc. 2nd Japan-China International Symposium on Ring Theory(1995), Okayama(1996), 41-44.
  6. Y. Talebi and N. Vanaja, The torsion theory cogenerated by M-small modules, Comm. Algebra, 30(3)(2002), 1449-1460. https://doi.org/10.1080/00927870209342390
  7. R. Wisbauer, Foundations of Moudule and Ring Theory, Gordon and Breach: Philadelphia, 1991.
  8. S. H. Mohamed and B. J. Muller, Continuous and Discrete Modules, London Math. Soc.; LNS147, Cambridge Univ. Press: Cambridge, 1990.
  9. D. Keskin, Finite direct sums of (D1)-modules, Tr. J. of Mathematics, 22(1998), 85-91.
  10. H. Zoxchinger, Minimax-Moduln, J. Algebra, 102(1986), 1-32. https://doi.org/10.1016/0021-8693(86)90125-0
  11. L. Ganesan and N. Vanaja, Modules for which every submodule has a unique coclosure, Comm. Algebra, 30(5)(2002), 2355-2377. https://doi.org/10.1081/AGB-120003473
  12. D. Keskin, Characterizations of right perfect rings by ${\oplus}$-supplemented modules, Contemp. Math., 259(2000), 313-318. https://doi.org/10.1090/conm/259/04103