Logarithmic conformal field theories via logarithmic deformations Original Research Article

We construct logarithmic conformal field theories starting from an ordinary conformal field theory—with a chiral algebra C and the corresponding space of states V—via a two-step construction: (i) deforming the chiral algebra representation on V⊗EndK[[z,z−1]], where K is an auxiliary finite-dimensional vector space, and (ii) extending C by operators corresponding to the endomorphisms EndK. For K=C2, with EndK being the two-dimensional Clifford algebra, our construction results in extending C by an operator that can be thought of as ∂−1E, where ∮E is a fermionic screening. This covers the (2,p) Virasoro minimal models as well as the sl(2) WZW theory.