1012.4198 (Yi-Zhi Huang et al.)

Logarithmic tensor category theory, IV: Constructions of tensor product
bifunctors and the compatibility conditions    [PDF]

Yi-Zhi Huang, James Lepowsky, Lin Zhang

This is the fourth part in a series of papers in which we introduce and develop a natural, general tensor category theory for suitable module categories for a vertex (operator) algebra. In this paper (Part IV), we give constructions of the P(z)- and Q(z)-tensor product bifunctors using what we call "compatibility conditions" and certain other conditions.

View original: http://arxiv.org/abs/1012.4198