Twisted vertex operators and unitary Lie algebras
  A representation of the central extension of the unitary Lie algebra coordinated with a skew Laurent polynomial ring is constructed using vertex operators over an integral Z_2-lattice. The irreducible decomposition of the representation is explicitly computed and described. As a by-product, some fundamental representations of affine Kac-Moody Lie algebra of type $A_n^{(2)}$ are recovered by the new method. 
Fulin Chen, Yun Gao, Naihuan Jing, Shaobin Tan
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