The Cardy-Cartan modular invariant

Abstract

Using factorizable Hopf algebras, we construct modular invariant partition functions of charge conjugation, or Cardy, type as characters of coends in categories that share essential features with the ones appearing in logarithmic CFT. The coefficients of such a partition function are given by the Cartan matrix of the theory.

extended version of a contribution to the Maximilian Kreuzer Memorial Volume. v2: typos corrected