Correlations in the far-infrared background

We compute the expected angular power spectrum of the cosmic far infrared background (FIRB). We find that the signal due to source correlations dominates the shot noise for l less than or similar to 1000 and results in anisotropies with rms amplitudes [l(l + 1)C-l/2 pi](1/2) between 5% and 10% of the mean for l greater than or similar to 150. The angular power spectrum depends on several unknown quantities, such as the UV flux density evolution, optical properties of the dust, biasing of the sources of the FIRE, and cosmological parameters. However, when we require our models to reproduce the observed direct current level of the FIRE, we find that the anisotropy is at least a few percent in all cases. This anisotropy is detectable with proposed instruments, and its measurement will provide strong constraints on models of galaxy evolution and large-scale structure at redshifts up to at least z similar to 5.