CFA modules and the finiteness of coassociated primes of local homology modules

Abstract

We introduce the concept CFA modules and their applications in investigation the coassociated primes of local homology modules. The main result of this paper says that if $M$ is a CFA linearly compact $R$-module and $t$ is a non-negative integer such that H i I ( M ) is CFA for all $i < t$, then R / I ⊗ R H t I ( M ) is CFA. Hence, the set $\mathrm{Coass}_R$ H t I ( M ) is finite.