Generalized rigid modules and their polynomial extensions

Let $R$ be a ring with unity, $\sigma$ an endomorphism of $R$ and $M_R$ a right $R$-module. In this paper, we continue studding $\sigma$-rigid modules that were introduced by Gunner et al. \cite{generalized/rigid}. We give some results on $\sigma$-rigid modules and related concepts. Also, we study the transfer of $\sigma$-rigidness from a module $M_R$ to its extensions, as triangular matrix modules and polynomial modules.