Continuous Gabor transform for semi-direct product of locally compact groups

Abstract

Let $H$ be a locally compact group, $K$ be an LCA group, $τ:H\to Aut(K)$ be a continuous homomorphism and $G_τ=H\ltimes_τK$ be the semi-direct product of $H$ and $K$ with respect to the continuous homomorphism $τ$. In this article we introduce the $τ\times\hatτ$-time frequency group $G_{τ\times\hatτ}$. We define the $τ\times\hatτ$-continuous Gabor transform of $f\in L^2(G_τ)$ with respect to a window function $u\in L^2(K)$ as a function defined on $G_{τ\times\hatτ}$. It is also shown that the $τ\times\hatτ$-continuous Gabor transform satisfies the Plancherel Theorem and reconstruction formula. This approach is tailored for choosing elements of $L^2(G_τ)$ as a window function. Finally, we illustrate application of these methods in the case of some well-known semi-direct product groups.