Torsion functors, small or large

Fred Rohrer

Let $\mathfrak{a}$ be an ideal in a commutative ring $R$. For an $R$-module $M$, we consider the small $\mathfrak{a}$-torsion $Γ_{\mathfrak{a}}(M)=\{x\in M\mid\exists n\in\mathbb{N…