Representations of vertex operator algebra V_L^+ for rank one lattice L

The irreducible modules of the 2-cycle permutation orbifold models of lattice vertex operator algebras of rank 1 are classified, the quantum dimensions of irreducible modules and the fusion rules are determined.

We continue the study of the vertex operator algebra $L(k,0)$ associated to a type $G_2^{(1)}$ affine Lie algebra at admissible one-third integer levels, $k = -2 + m + \tfrac{i}{3}\ (m\in \mathbb{Z}_{\ge 0}, i = 1,2)$, initiated in \cite{AL}. Our main result is that there is a finite number of irreducible $L(k,0)$-modules from the category $\mathcal{O}$. The proof relies on the knowledge of an explicit formula for the singular vectors. After obtaining this formula, we are abl...

Let $L(-{1/2}(l+1),0)$ be the simple vertex operator algebra associated to an affine Lie algebra of type $A_{l}^{(1)}$ with the lowest admissible half-integer level $-{1/2}(l+1)$, for even l. We study the category of weak modules for that vertex operator algebra which are in category $\cal{O}$ as modules for the associated affine Lie algebra. We classify irreducible objects in that category and prove semisimplicity of that category.

In this note we construct a series of singular vectors in universal affine vertex operator algebras associated to $D_{\ell}^{(1)}$ of levels $n-\ell+1$, for $n \in \Z_{>0}$. For $n=1$, we study the representation theory of the quotient vertex operator algebra modulo the ideal generated by that singular vector. In the case $\ell =4$, we show that the adjoint module is the unique irreducible ordinary module for simple vertex operator algebra $L_{D_{4}}(-2,0)$. We also show that...

In this paper, we study the algebra of twisted vertex operators over an even integral ${\mathbf Z}_2$-lattice, and give a kind of systematic construction of fundamental representations for affine Lie algebras of type $A$, $D$, $E$ with their irreducible decompositions.

It is the second paper in a series devoted to the investigation of characterizations of the exceptional vertex operator algebras of central charge 1. In this paper, we give a characterization of the rational vertex operator algebra VOL, where L is the root lattice of type A1 and O is the octahedral group.

We investigate vertex operator algebras $L(k,0)$ associated with modular-invariant representations for an affine Lie algebra $A_1 ^{(1)}$ , where k is 'admissible' rational number. We show that VOA $L(k,0)$ is rational in the category $\cal O$ and find all irreducible representations in the category of weight modules.

In this paper, we introduce and study some new classes of subalgebras of the lattice vertex operator algebras, which we call the Borel-type and parabolic-type subVOAs. For the lowest-rank examples of Borel-type subVOAs $V_{B}$ of $V_{\Z\al}$, and one nontrivial lowest-rank example of the parabolic-type subVOA $V_P$ of the lattice VOA $V_{A_2}$ associated to the root lattice $A_2$, we explicitly determine their Zhu's algebras $A(V_B)$ and $A(V_P)$ in terms of generators and re...

We determine the decomposition of V_{\sqrt{2}D_l} into a sum of irreducible T-modules for general l where D_l is the root lattice of type D_l and T is the tensor product of l+1 Virasoro vertex operator algebras with central charges c_{1}=1/2, c_{2}=7/10, c_{3}=4/5, and c_{i}=1 for 4\le i\le l+1.

For vertex operator algebra V_{\sqrt{2}A_l} associated to the even lattice \sqrt{2}A_l which is \sqrt{2} times root lattice of type A_l, it was shown by Dong-Li-Maosn-Norton that the Virasoro vector is a sum of l+1 mutually orthogonal conformal vectors with central charges c_i=1-6/(i+2)(i+3) for i=1,...,l and c_{l+1}=2l/(l+3) and the subalgebra T generated by these vectors is a tensor product of Virasoro vertex operator algebras L(c_i,0). In this paper we determine the decomp...