Consider a discrete group G and a bounded self-adjoint convolution operator T on l2 (G); let σ (T) be the spectrum of T. The spectral theorem gives a unitary isomorphism U between l2 (G) and a direct ...

Sigma-delta converters are in wide use among applications that demand high precision and accuracy. A variant of the sigma-delta architecture, called the continuous-time sigma delta (CT-S?), has found ...