English

Unravelling Mathieu Moonshine

High Energy Physics - Theory 2018-10-30 v3 Number Theory Representation Theory

Abstract

The D1-D5-KK-p system naturally provides an infinite dimensional module graded by the dyonic charges whose dimensions are counted by the Igusa cusp form, Phi_{10}(Z)$. We show that the Mathieu group, M_{24}, acts on this module by recovering the Siegel modular forms that count twisted dyons as a trace over this module. This is done by recovering Borcherds product formulae for these modular forms using the M_{24} action. This establishes the correspondence (`moonshine') proposed in arXiv:0907.1410 that relates conjugacy classes of M_{24} to Siegel modular forms. This also, in a sense that we make precise, subsumes existing moonshines for M_{24} that relates its conjugacy classes to eta-products and Jacobi forms.

Cite

@article{arxiv.1106.5715,
  title  = {Unravelling Mathieu Moonshine},
  author = {Suresh Govindarajan},
  journal= {arXiv preprint arXiv:1106.5715},
  year   = {2018}
}

Comments

20 pages; v2: New subsection on non-symplectic cases added v3: Some typos (a couple of sign errors) fixed

R2 v1 2026-06-21T18:28:44.728Z