English

On odd-spin $A_{1}^{(1)}$-string functions, cross-spin identities, and mock theta conjecture-like identities

Number Theory 2026-03-11 v2 Representation Theory

Abstract

Determining the explicit forms and modularity for string functions and branching coefficients for Kac--Moody algebras after Kac, Peterson, and Wakimoto is a long-standing, yet wide-open, problem and recently a connection has been made between positive admissible-level A1(1)A_{1}^{(1)}-string functions and Ramanujan's mock theta functions. In this paper we obtain the polar-finite decomposition for the admissible-level A1(1)A_{1}^{(1)} character of odd spin, and we also find new mock theta conjecture-like identities for the odd-spin, 2/32/3-level and 2/52/5-level A1(1)A_{1}^{(1)}-string functions.

Keywords

Cite

@article{arxiv.2603.08437,
  title  = {On odd-spin $A_{1}^{(1)}$-string functions, cross-spin identities, and mock theta conjecture-like identities},
  author = {Stepan Konenkov and Eric T. Mortenson},
  journal= {arXiv preprint arXiv:2603.08437},
  year   = {2026}
}

Comments

43 pages! The proofs in Section 6 no longer use the results of Frye and Garvan