The Z2-orbifold of the universal affine vertex algebra

Twistfield Perturbations of Vertex Operators in the Z2-Orbifold Model

Abstract: We apply Kadanoff’s theory of marginal deformations of conformal field theories to twistfield deformations of Z2 orbifold models in K3 moduli space. These deformations lead away from the Z2 orbifold sub-moduli-space and hence help to explore conformal field theories which have not yet been understood. In particular, we calculate the deformation of the conformal dimensions of vertex op...

Fusion rules for the free bosonic orbifold vertex operator algebra

Fusion rules among irreducible modules for the free bosonic orbifold vertex operator algebra are completely determined.

A Z2-orbifold model of the symplectic fermionic vertex operator superalgebra

We give an example of an irrational C2-cofinite vertex operator algebra whose central charge is −2d for any positive integer d. This vertex operator algebra is given as the even part of the vertex operator superalgebra generated by d pairs of symplectic fermions, and it is just the realization of the c = −2-triplet algebra given by Kausch in the case d = 1. We also classify irreducible modules ...

The Orbifold Topological Vertex

We define Donaldson-Thomas invariants of Calabi-Yau orbifolds and we develop a topological vertex formalism for computing them. The basic combinatorial object is the orbifold vertex V λμν , a generating function for the number of 3D partitions asymptotic to 2D partitions λ, μ, ν and colored by representations of a finite Abelian group G acting on C. In the case where G ∼= Zn acting on C with tr...

Vertex Operator Algebra Structure of Standard Affine Lie Algebra Modules