English

Ising vectors in the vertex operator algebra $V_{\Lambda}^+$ associated with the Leech lattice $\Lambda$

Quantum Algebra 2008-10-31 v1 Group Theory

Abstract

In this article, we study the Ising vectors in the vertex operator algebra VΛ+V_\Lambda^+ associated with the Leech lattice Λ\Lambda. The main result is a characterization of the Ising vectors in VΛ+V_\Lambda^+. We show that for any Ising vector ee in VΛ+V_\Lambda^+, there is a sublattice E2E8E\cong \sqrt{2}E_8 of Λ\Lambda such that eVE+e\in V_E^+. Some properties about their corresponding τ\tau-involutions in the moonshine vertex operator algebra VV^\natural are also discussed. We show that there is no Ising vector of σ\sigma-type in VV^\natural. Moreover, we compute the centralizer C\autV(z,τe)C_{\aut V^\natural}(z, \tau_e) for any Ising vector eVΛ+e\in V_\Lambda^+, where zz is a 2B element in \autV\aut V^\natural which fixes VΛ+V_\Lambda^+. Based on this result, we also obtain an explanation for the 1A case of an observation by Glauberman-Norton (2001), which describes some mysterious relations between the centralizer of zz and some 2A elements commuting zz in the Monster and the Weyl groups of certain sublattices of the root lattice of type E8E_8 .

Cite

@article{arxiv.0810.5395,
  title  = {Ising vectors in the vertex operator algebra $V_{\Lambda}^+$ associated with the Leech lattice $\Lambda$},
  author = {Ching Hung Lam and Hiroki Shimakura},
  journal= {arXiv preprint arXiv:0810.5395},
  year   = {2008}
}

Comments

22 pages

R2 v1 2026-06-21T11:36:25.200Z