Essentially Retractable Modules

author

  • M.R. Vedadi Department of Mathematical Sciences, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran
Abstract:

We call a module  essentially retractable if HomR for all essential submodules N of M. For a right FBN ring R, it is shown that: (i)  A non-zero module  is retractable (in the sense that HomR for all non-zero ) if and only if certain factor modules of M are essentially retractable nonsingular modules over R modulo their annihilators. (ii)  A non-zero module  is essentially retractable if and only if there exists a prime ideal  such that HomR. Over semiprime right nonsingular rings, a nonsingular essentially retractable module is precisely a module with non-zero dual. Moreover, over certain rings R, including right FBN rings, it is shown that a nonsingular module M with enough uniforms is essentially retractable if and only if there exist uniform retractable R-modules  and R-homomorphisms  with .

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Journal title

volume 18  issue 4

pages  355- 360

publication date 2007-12-01

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