Sampling Theorem and Discrete Fourier Transform on the Hyperboloid

Using Coherent-State (CS) techniques, we prove a sampling theorem for holomorphic functions on the hyperboloid (or its stereographic projection onto the open unit disk D1), seen as a homogeneous space of the pseudo-unitary group SU(1, 1). We provide a reconstruction formula for bandlimited functions, through a sinc-type kernel, and a discrete Fourier transform from N samples properly chosen. We also study the case of undersampling of “quasi-bandlimited” functions and the conditions under which a partial reconstruction from N samples is still possible and the accuracy of the approximation.