  This paper investigates structure of Banach convolution modules induced by
group algebras on covariant functions of characters of closed normal subgroups.
Let $G$ be a locally compact group with the group algebra $L^1(G)$ and $N$ be a
closed normal subgroup of $G$. Suppose that $\xi:N\to\mathbb{T}$ is a
continuous character, $1\le p<\infty$ and $L_\xi^p(G,N)$ is the $L^p$-space of
all covariant functions of $\xi$ on $G$. It is shown that $L^p_\xi(G,N)$ is a
Banach $L^1(G)$-module. We then study convolution module actions of group
algebras on covariant functions of characters for the case of canonical normal
subgroups in semi-direct product groups.

Functional Analysis