Strictly supercritical sampling alias counterexample

ID: strictly-supercritical-sampling-alias-counterexample

For every , choose a nonzero smooth spectral bump supported in with , and let be its inverse Fourier transform. Then is a nonzero Schwartz function, vanishes on all integer samples, and its transform is the difference of bumps shifted to and . Its support lies strictly within . Thus even a small bandwidth increase destroys uniqueness from unit-spaced samples.

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