Lift of the trivial representation to a nonlinear double cover

Abstract

Let $\widetilde G$ be the nonlinear double cover of the real points of a connected, simply connected, semisimple complex group. In [Ts], we introduce a set of genuine small representations of $\widetilde G$ with infinitesimal character $\lambda$, denoted $\prod _\lambda ^s (\widetilde G)$. In this paper, we show that $\prod _{\rho/2} ^s (\widetilde G)$ is precisely the set of genuine irreducible representations arising from the Kazhdan-Patterson lifting of the trivial representation, when $\widetilde G$ is simply laced and split.