An algebraic approach to logarithmic conformal field theory
Matthias R Gaberdiel
TL;DR
Gaberdiel develops an algebraic framework for logarithmic conformal field theory, emphasizing indecomposable representations and Zhu's algebra as essential tools. He works through the $c=-2$ triplet model to show how logarithmic structure arises in fusion, modular properties, and the partition function, and demonstrates an explicit local theory equivalent to the bosonic sector of symplectic fermions. He then extends the discussion to fractional level WZW models, notably $k=-4/3$ for $\mathfrak{su}(2)$, where logarithmic representations appear in fusion and are organized by an outer automorphism symmetry. The work argues that many non-rational CFTs are naturally logarithmic and provides a general, algebraic pathway to understanding their representation theory and modular behavior.
Abstract
A comprehensive introduction to logarithmic conformal field theory, using an algebraic point of view, is given. A number of examples are explained in detail, including the c=-2 triplet theory and the k=-4/3 affine su(2) theory. We also give some brief introduction to the work of Zhu.
