In logarithmic conformal field theory, primary fields come together with
logarithmic partner fields on which the stress-energy tensor acts
non-diagonally. Exploiting this fact and global conformal invariance of two-
and three-point functions, operator product expansions of logarithmic operators
in arbitrary rank logarithmic conformal field theory are investigated. Since
the precise relationship between logarithmic operators and their primary
partners is not yet sufficiently understood in all cases, the derivation of
operator product expansion formulae is only possible under certain assumptions.
The easiest cases are studied in this paper: firstly, where operator product
expansions of two primaries only contain primary fields, secondly, where the
primary fields are pre-logarithmic operators. Some comments on generalization
towards more relaxed assumptions are made, in particular towards the case where
logarithmic fields are not quasi-primary. We identify an algebraic structure
generated by the zero modes of the fields, which proves useful in determining
settings in which our approach can be successfully applied.Comment: 30+1 pages LaTeX2e. Version to be published. Major rework and
extensio