$2$-Periodic complexes over regular local rings

Abstract

Let $(A,\mathfrak{m})$ be a regular local ring of dimension $d \geq 1$. Let $\mathcal{D}^2_{fg}(A)$ denote the derived category of $2$-periodic complexes with finitely generated cohomology modules. Let $\mathcal{K}^2(\proj A) $ denote the homotopy category of $2$-periodic complexes of finitely generated free $A$-modules. We show the natural map $\mathcal{K}^2(\ proj \ A) \longrightarrow \mathcal{D}^2(A)$ is an equivalence of categories. When $A$ is complete we show that $\mathcal{K}^2_f(\ proj \ A)$ ($2$-periodic complexes with finite length cohomology) is Krull-Schmidt with Auslander-Reiten (AR) triangles. We also compute the AR-quiver of $\mathcal{K}^2_f(\ proj \ A)$ when $\ dim \ A = 1$.