ADE subalgebras of the triplet vertex algebra W(p): A-series
arXiv:1212.5453
Abstract
Motivated by \cite{am1}, for every finite subgroup we investigate the fixed point subalgebra $\triplet^Γ$ of the triplet vertex , of central charge , . This part deals with the -series in the ADE classification of finite subgroups of . First, we prove the -cofiniteness of the -fixed subalgebra $\triplet^{A_m}$. Then we construct a family of $\am$-modules, which are expected to form a complete set of irreps. As a strong support to our conjecture, we prove modular invariance of (generalized) characters of the relevant (logarithmic) modules. Further evidence is provided by calculations in Zhu's algebra for . We also present a rigorous proof of the fact that the full automorphism group of $\triplet$ is .
24 pages. To appear in Communications of Contemporary Mathematics