2015/02/28 by Bojko Bakalov, Jason Elsinger · 1 citation
Mathematics · #math.QA #msc:17B69 #msc:81R10
paper · pdf · doi:10.1016/j.jalgebra.2015.06.028
published as Journal of Algebra 441 (2015), 57-83 · 27 pages; v2 typos fixed and a reference added
arxiv created 2015/07/17 · arxiv updated 2015/12/04
Every isometry σ of a positive-definite even lattice Q can be lifted to an automorphism of the lattice vertex algebra VQ. An important problem in vertex algebra theory and conformal field theory is to classify the representations of the σ-invariant subalgebra VQσ of VQ, known as an orbifold. In the case when σ is an isometry of Q of order two, we classify the irreducible modules of the orbifold vertex algebra VQσ and identify them as submodules of twisted or untwisted VQ-modules. The examples where Q is a root lattice and σ is a Dynkin diagram automorphism are presented in detail.