MODULES WHOSE CERTAIN SUBMODULES ARE ESSENTIALLY EMBEDDED IN DIRECT SUMMANDS


KARA Y. , TERCAN A.

ROCKY MOUNTAIN JOURNAL OF MATHEMATICS, vol.46, no.2, pp.519-532, 2016 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 46 Issue: 2
  • Publication Date: 2016
  • Doi Number: 10.1216/rmj-2016-46-2-519
  • Title of Journal : ROCKY MOUNTAIN JOURNAL OF MATHEMATICS
  • Page Numbers: pp.519-532

Abstract

It is well known that, if the ring has acc on essential right ideals, then for every quasi-continuous module over the ring, the finite exchange property implies the full exchange property. In this paper, we obtain the former implication for the generalizations of quasi-continuous modules over a ring with acc on right annhilators of elements of the module. Moreover, we focus on direct sums and direct summands of weak C-12 modules i.e., modules with the property that every semisimple submodule can be essentially embedded in a direct summand. To this end, we prove that since weak C-12 is closed under direct sums. Amongst other results, we provide several counterexamples including the tangent bundle of a real sphere of odd dimension over its coordinate ring for the open problem of whether weak C-12 implies the C-12 condition.