  We derive and study a theoretical description for single file diffusion,
i.e., diffusion in a one dimensional lattice of particles with hard core
interaction. It is well known that for this system a tagged particle has
anomalous diffusion for long times. The novelty of the present approach is that
it allows for the derivation of correlations between a tagged particle and
other particles of the system at a given distance with empty sites in between.
The behavior of the correlation gives deeper insights into the processes
involved. Numerical integration of differential equations are in good agreement
with Monte Carlo simulations.
