Super formal Daboux-Weinstein theorem and finite W superalgebra

Abstract

Let $\vvv=\vvv_{\bar{0}}+\vvv_{\bar{1}}$ be a $\mathbb{Z}_2$-graded (super) vector space with an even $\mathbb{C}^{\times}$-action and $\chi \in \vvv_{\bar{0}}^{*}$ be a fixed point of the induced action. In this paper we will prove a equivariant Daboux-Weinstein theorem for the formal polynomial algebras $\hat{A}=S[\vvv_{\bar{0}}]^{\wedge_{\chi}}\otimes \bigwedge(\vvv_{\bar{1}})$. We also give a quantum version of the equivariant Daboux-Weinstein theorem. Let $\ggg=\ggg_{\bar{0}}+\ggg_{\bar{1}}$ a basic Lie superalgebra of type I and $e \in \ggg_{\bar{0}}$ be a nilpotent element. We will use the equivariant quantum Daboux-Weinstein theorem to realize the finite $W$ superalgebra $\mathcal{U}(\ggg,e)$. An indirect relation between finite U(g,e) and U(g_{\bar{0}} ,e) is presented. Finally we will use this realization to study the finite dimensional representations of $\mathcal{U}(\ggg,e)$.