On rationality of C-graded vertex algebras and applications to Weyl vertex algebras under conformal flow

Abstract

Using the Zhu algebra for a certain category of [Formula: see text]-graded vertex algebras V, we prove that if V is finitely Ω-generated and satisfies suitable grading conditions, then V is rational, i.e., it has semi-simple representation theory, with a one-dimensional level zero Zhu algebra. Here, Ω denotes the vectors in V that are annihilated by lowering the real part of the grading. We apply our result to the family of rank one Weyl vertex algebras with conformal element ω μ parameterized by [Formula: see text] and prove that for certain non-integer values of μ, these vertex algebras, which are non-integer graded, are rational, with a one-dimensional level zero Zhu algebra. In addition, we generalize this result to appropriate [Formula: see text]-graded Weyl vertex algebras of arbitrary ranks.