English

Two $2/5$-level mock theta conjecture-like identities

Number Theory 2025-10-08 v1

Abstract

Determining the explicit forms and modularity for string functions and branching coefficients for Kac--Moody algebras after Kac, Peterson, and Wakimoto is an important problem. In a pair of papers, Borozenets and Mortenson determined the explicit forms for fractional-level string functions for the Kac--Moody algebra A1(1)A_{1}^{(1)}. For positive fractional-level string functions they obtained mock theta conjecture-like identities, and for negative fractional-level string functions, they obtained mixed false theta function expressions. Here we find two new families of mock theta conjecture-like identities but for the 2/52/5-level string functions. Each of these two families of identities is composed of the four tenth-order mock theta functions from Ramanujan's Lost Notebook as well as a simple quotient of theta functions.

Keywords

Cite

@article{arxiv.2506.01886,
  title  = {Two $2/5$-level mock theta conjecture-like identities},
  author = {Stepan Konenkov and Eric T. Mortenson},
  journal= {arXiv preprint arXiv:2506.01886},
  year   = {2025}
}
R2 v1 2026-07-01T02:54:50.607Z