arXiv subjects

Josh Pollitz

Publications and source records attributed to Josh Pollitz.

21 records · Page 2Linked to original sources

arXiv2020

Duality and symmetry of complexity over complete intersections via exterior homology

We study homological properties of a locally complete intersection ring by importing facts from homological algebra over exterior algebras. One application is showing that the thick subcategories of the bounded derived category of a locally complete intersection ring are self-dual under Grothendieck duality. This was proved by Stevenson when the ring is a quotient of a regular ring modulo a regular sequence; we offer two independent proofs in the more general setting. Second, we use these techniques to supply new proofs that complete intersections possess symmetry of complexity.

math.AC↗

arXiv2019

Equivariant isomorphisms of Ext and Tor modules

In this article we establish equivariant isomorphisms of Ext and Tor modules over different relative complete intersections. More precisely, for a commutative ring $Q$, this paper investigates how $Ext_{Q/(\boldsymbol{f})}^*(M,N)$ and $Tor^{Q/(\boldsymbol{f})}_*(M,N)$ change when one varies $\boldsymbol{f}$ among all Koszul-regular sequences of a fixed length such that $\boldsymbol{f} M=0$ and $\boldsymbol{f} N=0$. Of notable interest is how the theory of perturbations is used to establish isomorphisms of certain DG modules.

math.AC↗

arXiv2018

The derived category of a locally complete intersection ring

In this paper, we answer a question of Dwyer, Greenlees, and Iyengar by proving a local ring $R$ is a complete intersection if and only if every complex of $R$-modules with finitely generated homology is proxy small. Moreover, we establish that a commutative noetherian ring $R$ is locally a complete intersection if and only if every complex of $R$-modules with finitely generated homology is virtually small.

math.AC↗