We will describe the Ziegler spectrum over the ring of entire complex valued functions.

In this note, we have obtained a Whitehead-like tower of a module by considering a suitable set of morphisms and shown that the different stages of the tower are the Adams cocompletions of the module with respect to the suitably chosen set of morphisms.

Let (R,m) be a local ring, and let M and N be finite R-modules. In this paper we give a formula for the degree of the polynomial giving the lengths of the modules ExtiR(M,N/mnN). A number of corollaries are given, and more general filtrations are also considered.

Let R be a noetherian commutative ring, and

a complex of flat R-modules. We prove that if is acyclic for every ρ ϵ Spec R, then is acyclic, and H0() is R-flat. It follows that if is a (possibly unbounded) complex of flat R-modules and is exact for every ρ ϵ Spec R, then is exact for every R-complex . If, moreover, is a complex of projective R-modules, then it is null-homotopic (follows from Neeman’s theorem).

If $F$ and ${F}'$ are free $R$-modules, then $M\cong F/H$ and $M\,\cong \,{F}'\,/\,{H}'$ are viewed as equivalent presentations of the $R$-module $M$ if there is an isomorphism $F\,\to \,{F}'$ which carries the submodule $H$ onto ${H}'$. We study when presentations of modules of projective dimension 1 over Prüfer domains of finite character are necessarily equivalent.

We consider graded connected Gorenstein algebras with respect to the evaluation map $\text{e}{{\text{v}}_{G\,}}\,=\,\text{Ex}{{\text{t}}_{G}}(k,\varepsilon )\,::\,\text{Ex}{{\text{t}}_{G}}(k,G)\,\to \,\text{Ex}{{\text{t}}_{G}}(k,k)$. We prove that if $e{{v}_{G}}\,\ne \,0$, then the global dimension of $G$ is finite.

Let R be an integral domain with quotient field K and let I be a nonzero ideal of R. We show (1) that I is invertible if and only if for every nonempty collection {Bα} of ideals of R and (2) that I is flat if and only if I(B ∩ C) = IB∩IC for each pair of ideals B and C of R.