Twisted toroidal Lie algebras and Moody-Rao-Yokonuma presentation

摘要

Let g be a(twisted or untwisted)affine Kac-Moody algebra,andμbe a diagram automorphism of g.In this paper,we give an explicit realization for the universal central extensionˆg[μ]of the twisted loop algebra of g with respect toμ,which provides a Moody-Rao-Yokonuma presentation for the algebraˆg[μ]whenμis non-transitive,and the presentation is indeed related to the quantization of twisted toroidal Lie algebras.