Gabor (Super)Frames with Hermite Functions

Karlheinz Gröchenig, Yurii Lyubarskii

Published 2008-04-29Version 1

We investigate vector-valued Gabor frames (sometimes called Gabor superframes) based on Hermite functions $H_n$. Let $h= (H_0, H_1, ..., H_n)$ be the vector of the first $n+1$ Hermite functions. We give a complete characterization of all lattices $\Lambda \subseteq \bR ^2$ such that the Gabor system $\{e^{2\pi i \lambda_2 t} \boh (t-\lambda_1): \lambda = (\lambda_1, \lambda_2) \in \Lambda \}$ is a frame for $L^2 (\bR, \bC ^{n+1})$. As a corollary we obtain sufficient conditions for a single Hermite function to generate a Gabor frame and a new estimate for the lower frame bound. The main tools are growth estimates for the Weierstrass $\sigma $-function, a new type of interpolation problem for entire functions on the Bargmann-Fock space, and structural results about vector-valued Gabor frames.