Title of article :
Rings for which every simple module is almost injective
Author/Authors :
Arabi-Kakavand، Marzieh نويسنده Isfahan University of Technology , , Asgari، Shadi نويسنده Institute for Research in Fundamental Sciences (IPM) , , Khabazian، Hossein نويسنده Isfahan University of Technology ,
Issue Information :
دوماهنامه با شماره پیاپی 0 سال 2016
Abstract :
We introduce the class of ``right almost $V$-ringsʹʹ which is properly between the classes of right $V$-rings and right good rings. A ring $R$ is called a right almost $V$-ring if every simple $R$-module is almost injective. It is proved that $R$ is a right almost $V$-ring if and only if for every $R$-module $M$, any complement of every simple submodule of $M$ is a direct summand. Moreover, $R$ is a right almost $V$-ring if and only if for every simple $R$-module $S$, either $S$ is injective or the injective hull of $S$ is projective of length 2. Right Artinian right almost $V$-rings and right Noetherian right almost $V$-rings are characterized. A $2 \times 2$ upper triangular matrix ring over $R$ is a right almost $V$-ring precisely when $R$ is semisimple.
Journal title :
Bulletin of the Iranian Mathematical Society
Journal title :
Bulletin of the Iranian Mathematical Society