We consider large neutral atoms of atomic number Z. For such atoms the speed of electrons close to the nucleus is a substantial fraction of the speed of light. Thus, a relativistic description is mandatory. We show that the one particle ground state density on the (hydrogenic) Scott length scale, given by Z^{-1}, converges to the density of an infinite Bohr atom in the Chandrasekhar and Furry models. Eventually, we provide pointwise upper bounds for the latter.

The talk is based on joint works with Rupert L. Frank, Heinz Siedentop, and Barry Simon.