Whittaker modules for the planar Galilean conformal algebra and its central extension

TL;DR

This paper classifies and analyzes Whittaker modules for the planar Galilean conformal algebra and its central extension, establishing conditions for irreducibility and explicitly constructing submodules.

Contribution

It provides a classification of universal and generic Whittaker modules, and characterizes their irreducibility based on the nonsingularity of the homomorphism.

Findings

Classified isomorphism classes of Whittaker modules.

Established irreducibility criteria for generic Whittaker modules.

Constructed submodules in the singular case.

Abstract

Let $\mathcal{G}$ be the planar Galilean conformal algebra and $\widetilde{\mathcal{G}}$ be its universal central extension. Then $\mathcal{G}$ (resp. $\widetilde{\mathcal{G}}$) admits a triangular decomposition: $\mathcal{G}=\mathcal{G}^{+}\oplus\mathcal{G}^{0}\oplus\mathcal{G}^{-}$ (resp. $\widetilde{\mathcal{G}}=\widetilde{\mathcal{G}}^{+}\oplus\widetilde{\mathcal{G}}^{0}\oplus\widetilde{\mathcal{G}}^{-}$). In this paper, we study universal and generic Whittaker $\mathcal{G}$-modules (resp. $\widetilde{\mathcal{G}}$-modules) of type $\phi$, where $\phi:\mathcal{G}^{+}=\widetilde{\mathcal{G}}^{+}\longrightarrow\mathbb{C}$ is a Lie algebra homomorphism. We classify the isomorphism classes of universal and generic Whittaker modules. Moreover, we show that a generic Whittaker modules of type $\phi$ is irreducible if and only if $\phi$ is nonsingular. For the nonsingular case, we completely determine the Whittaker vectors in universal and generic Whittaker modules. For the singular case, we concretely construct some proper submodules of generic Whittaker modules.