Modules-at-infinity for quantum vertex algebras
arXiv:0705.0687 · doi:10.1007/s00220-008-0534-1
Abstract
This is a sequel to \cite{li-qva1} and \cite{li-qva2} in a series to study vertex algebra-like structures arising from various algebras such as quantum affine algebras and Yangians. In this paper, we study two versions of the double Yangian , denoted by and with a nonzero complex number. For each nonzero complex number , we construct a quantum vertex algebra and prove that every -module is naturally a -module. We also show that -modules are what we call -modules-at-infinity. To achieve this goal, we study what we call -local subsets and quasi-local subsets of $\Hom (W,W((x^{-1})))$ for any vector space , and we prove that any -local subset generates a (weak) quantum vertex algebra and that any quasi-local subset generates a vertex algebra with as a (left) quasi module-at-infinity. Using this result we associate the Lie algebra of pseudo-differential operators on the circle with vertex algebras in terms of quasi modules-at-infinity.
Latex, 48 pages