Balanced root systems and a Schellekens-type list for holomorphic vertex operator algebras of central charge $32$
Maneesha Ampagouni, Geoffrey Mason, Michael H. Mertens
TL;DR
This work introduces balanced root systems for holomorphic VOAs with central charges $c=32$ and $c=40$, extending Niemeier/Schellekens-type data to include levels and supplemented root systems. It proves that for these charges, the VOA’s Virasoro vector aligns with the subVOA’s Virasoro structure, enabling a Schellekens-type classification where the root data satisfy a delicate balance condition. The authors derive explicit candidate root-system lists, analyze the realizability via lattice theories and DGM orbifolds, and employ modular and Jacobi-form constraints alongside computational tests to prune candidates. The combined theoretical and computational approach narrows the landscape to a finite set of possible structures, providing concrete classifications and laying groundwork for further exploration of higher central charges in holomorphic VOAs.
Abstract
We study a special class of holomorphic vertex operator algebras (VOAs) that we call \emph{balanced}.\ For a balanced, holomorphic VOA $V=\mathbb{C}\mathbf{1}\oplus V_1\oplus\dots$ with $c=32$ or $40$ we show that the Virasoro vectors of $V$ and the subVOA generated by $V_1$ coincide and use this result to provide a Schellekens-type list of possible root systems that may occur.
