Maximally correlated fields

We introduce an averaging transformation in which the value of the field at a particular point is replaced by the average over some neighborhood of th at point. The similarity of the field increases due to this transformation and hence the field becomes more correlated. The sinc-correlated field; how ever, does not change its shape under this transformation, and this implies the sine-correlated field is maximally correlated rather than minimally co rrelated. The universal spectral degree of coherence is reexamined in view of the averaging transformation.