The KZ system via polydifferentials

Eduard Looijenga

Abstract

We show that the KZ system has a topological interpretation in the sense that it may be understood as a variation of complex mixed Hodge structure whose successive pure weight quotients are polarized. This in a sense completes and elucidates work of Schechtman–Varchenko done in the early 1990's. A central ingredient is a new realization of the irreducible highest weight representations of a Lie algebra of Kac–Moody type, namely on an algebra of rational polydifferentials on a countable product of Riemann spheres. We also obtain the kind of properties that in the $\mathfrak{sl} (2)$ case are due to Ramadas and are then known to imply the unitarity of the WZW system in genus zero.

Article information

Dates
Revised: 11 January 2011
First available in Project Euclid: 24 November 2018

https://projecteuclid.org/ euclid.aspm/1543085010

Digital Object Identifier
doi:10.2969/aspm/06210189

Mathematical Reviews number (MathSciNet)
MR2933798

Zentralblatt MATH identifier
1260.32004

Citation

Looijenga, Eduard. The KZ system via polydifferentials. Arrangements of Hyperplanes — Sapporo 2009, 189--231, Mathematical Society of Japan, Tokyo, Japan, 2012. doi:10.2969/aspm/06210189. https://projecteuclid.org/euclid.aspm/1543085010