A New Type of Intensity Correlation in Random Media

A monochromatic point source, embedded in a three-dimensional disordered medium, is considered. The resulting intensity pattern exhibits a new type of long-range correlations. The range of these correlations is infinite and their magnitude, normalized to the average intensity, is of order $1\mathrm{/}{k}_0\mathrm{\ell }$, where $k_0$ and $\mathrm{\ell }$ are the wave number and the mean free path respectively.