Indecomposable Supercharacters of the Infinite Unitriangular Group

Abstract

Let ${U}_{\infty}{(\mathbb{K})}$ be the locally finite unitriangular group defined over a finite field ${\mathbb{K}}$ with q elements. We define the notion of an indecomposable supercharacter and describe these indecomposable supercharacters in terms of the supercharacters of the finite unitriangular groups ${U}_{n}{(\mathbb{K})}$.