A remark on the $C_2$-cofiniteness condition on vertex algebras
Tomoyuki Arakawa
TL;DR
This work establishes that for finitely strongly generated, non-negatively graded vertex algebras, $C_2$-cofiniteness is equivalent to Beilinson–Feigin–Mazur lisse property, showing the two finiteness notions coincide in this setting. The authors develop and interconnect Li and standard filtrations, jet schemes, associated varieties, and singular supports to translate algebraic finiteness into geometric conditions, proving the main equivalence via the jet-scheme behavior of zero-dimensional varieties. They illustrate the framework with Virasoro and affine examples, demonstrating how $C_2$-cofiniteness aligns with classical notions like reducibility in Virasoro minimal models and integrability for affine algebras. The results provide a natural, geometric understanding of finiteness in vertex algebras and offer tools for studying a broad class of algebras, including $W$-algebras, through associated varieties and jet schemes.
Abstract
We show that a finitely strongly generated, non-negatively graded vertex algebra $V$ is $C_2$-cofinite if and only if it is lisse in the sense of Beilinson, Feigin and Mazur. This shows that the $C_2$-cofiniteness is indeed a natural finiteness condition.
