Asymptotic behavior of partial and false theta functions arising from Jacobi forms and regularized characters

Abstract

Motivated by recent developments in the representation theory of vertex algebras and conformal field theory, we prove several asymptotic results for partial and false theta functions arising from Jacobi forms, as the modular variable τ tends to 0 along the imaginary axis, and the elliptic variable z is unrestricted in the complex plane. We observe that these functions exhibit Stokes’ phenomenon—the asymptotic behavior of these functions sharply differs depending on where the elliptic variable z is located within the complex plane. We apply our results to study the asymptotic expansions of regularized characters and quantum dimensions of the (1, p)-singlet W-algebra modules important in logarithmic conformal field theory. This, in particular, recovers and extends several results from the work of T. Creutzig et al. [Int. Math. Res. Not. (2016); e-print arXiv:1411.3282] pertaining to regularized quantum dimensions.